diff --git a/external/json/.gitignore b/external/json/.gitignore
deleted file mode 100644
index b767889..0000000
--- a/external/json/.gitignore
+++ /dev/null
@@ -1,11 +0,0 @@
-*.html
-*.o
-*.so
-notes
-packages
-tags
-tests/utf8.dat
-*~
-*.swp
-go
-test_case.lua
diff --git a/external/json/.travis.yml b/external/json/.travis.yml
deleted file mode 100644
index 091ff98..0000000
--- a/external/json/.travis.yml
+++ /dev/null
@@ -1,63 +0,0 @@
-sudo: required
-dist: Focal
-
-os: linux
-
-language: c
-
-compiler:
-  - gcc
-
-addons:
-  apt:
-    packages:
-    - cppcheck
-    - valgrind
-    - cpanminus
-    - libipc-run3-perl
-    - lua5.1
-    - lua5.1-dev
-    - cmake
-
-cache:
-  apt: true
-
-env:
-  global:
-    - JOBS=3
-    - LUAROCKS_VER=2.4.2
-  matrix:
-      #- LUA=1 LUA_DIR=/usr LUA_INCLUDE_DIR=$LUA_DIR/include/lua5.1
-      - LUAJIT=1 LUA_DIR=/usr/local LUA_INCLUDE_DIR=$LUA_DIR/include/luajit-2.1 LUA_SUFFIX=--lua-suffix=jit
-
-install:
-    - sudo ln -s /usr/bin/cmake /usr/local/bin/cmake
-    - if [ -n "$LUAJIT" ]; then git clone -b v2.1-agentzh https://github.com/openresty/luajit2.git; fi
-    - if [ -n "$LUAJIT" ]; then cd ./luajit2; fi
-    - if [ -n "$LUAJIT" ]; then make -j$JOBS CCDEBUG=-g Q= PREFIX=$LUAJIT_PREFIX CC=$CC XCFLAGS='-DLUA_USE_APICHECK -DLUA_USE_ASSERT' > build.log 2>&1 || (cat build.log && exit 1); fi
-    - if [ -n "$LUAJIT" ]; then sudo make install > build.log 2>&1 || (cat build.log && exit 1); fi
-    - if [ -n "$LUAJIT" ]; then cd ..; fi
-    - if [ -n "$LUAJIT" ]; then sudo ln -s $LUA_DIR/bin/luajit $LUA_DIR/bin/lua; fi
-    - sudo cpanm --notest Test::Base Test::LongString > build.log 2>&1 || (cat build.log && exit 1)
-    - wget https://luarocks.github.io/luarocks/releases/luarocks-$LUAROCKS_VER.tar.gz
-    - tar -zxf luarocks-$LUAROCKS_VER.tar.gz
-    - cd luarocks-$LUAROCKS_VER
-    - ./configure --with-lua=$LUA_DIR --with-lua-include=$LUA_INCLUDE_DIR $LUA_SUFFIX
-    - make build
-    - sudo make install
-    - cd ..
-
-script:
-  - cppcheck -i ./luajit2 --force --error-exitcode=1 --enable=warning . > build.log 2>&1 || (cat build.log && exit 1)
-  - bash runtests.sh
-  - make
-  - prove -Itests tests
-  - TEST_LUA_USE_VALGRIND=1 prove -Itests tests > build.log 2>&1; export e=$?
-  - cat build.log
-  - grep -E '^==[0-9]+==' build.log; if [ "$?" == 0 ]; then exit 1; else exit $e; fi
-  - cmake -DUSE_INTERNAL_FPCONV=1 .
-  - make
-  - prove -Itests tests
-  - TEST_LUA_USE_VALGRIND=1 prove -Itests tests > build.log 2>&1; export e=$?
-  - cat build.log
-  - grep -E '^==[0-9]+==' build.log; if [ "$?" == 0 ]; then exit 1; else exit $e; fi
diff --git a/external/json/lua/cjson/util.lua b/external/json/lua/cjson/util.lua
deleted file mode 100644
index 7cf66be..0000000
--- a/external/json/lua/cjson/util.lua
+++ /dev/null
@@ -1,312 +0,0 @@
-local json = require "cjson"
-
-local unpack = unpack or table.unpack
-
-local maxn = table.maxn or function(t)
-    local max = 0
-    for k,v in pairs(t) do
-        if type(k) == "number" and k > max then
-            max = k
-        end
-    end
-    return max
-end
-
-local _one_of_mt = {}
-
-local function one_of(t)
-    setmetatable(t, _one_of_mt)
-    return t
-end
-
-local function is_one_of(t)
-    return type(t) == "table" and getmetatable(t) == _one_of_mt
-end
-
--- Various common routines used by the Lua CJSON package
---
--- Mark Pulford <mark@kyne.com.au>
-
--- Determine with a Lua table can be treated as an array.
--- Explicitly returns "not an array" for very sparse arrays.
--- Returns:
--- -1   Not an array
--- 0    Empty table
--- >0   Highest index in the array
-local function is_array(table)
-    local max = 0
-    local count = 0
-    for k, v in pairs(table) do
-        if type(k) == "number" then
-            if k > max then max = k end
-            count = count + 1
-        else
-            return -1
-        end
-    end
-    if max > count * 2 then
-        return -1
-    end
-
-    return max
-end
-
-local serialise_value
-
-local function serialise_table(value, indent, depth)
-    local spacing, spacing2, indent2
-    if indent then
-        spacing = "\n" .. indent
-        spacing2 = spacing .. "  "
-        indent2 = indent .. "  "
-    else
-        spacing, spacing2, indent2 = " ", " ", false
-    end
-    depth = depth + 1
-    if depth > 50 then
-        return "Cannot serialise any further: too many nested tables"
-    end
-
-    local max = is_array(value)
-
-    local comma = false
-    local prefix = "{"
-    if is_one_of(value) then
-        prefix = "ONE_OF{"
-    end
-    local fragment = { prefix .. spacing2 }
-    if max > 0 then
-        -- Serialise array
-        for i = 1, max do
-            if comma then
-                table.insert(fragment, "," .. spacing2)
-            end
-            table.insert(fragment, serialise_value(value[i], indent2, depth))
-            comma = true
-        end
-    elseif max < 0 then
-        -- Serialise table
-        for k, v in pairs(value) do
-            if comma then
-                table.insert(fragment, "," .. spacing2)
-            end
-            table.insert(fragment,
-                ("[%s] = %s"):format(serialise_value(k, indent2, depth),
-                                     serialise_value(v, indent2, depth)))
-            comma = true
-        end
-    end
-    table.insert(fragment, spacing .. "}")
-
-    return table.concat(fragment)
-end
-
-function serialise_value(value, indent, depth)
-    if indent == nil then indent = "" end
-    if depth == nil then depth = 0 end
-
-    if value == json.null then
-        return "json.null"
-    elseif type(value) == "string" then
-        return ("%q"):format(value)
-    elseif type(value) == "nil" or type(value) == "number" or
-           type(value) == "boolean" then
-        return tostring(value)
-    elseif type(value) == "table" then
-        return serialise_table(value, indent, depth)
-    else
-        return "\"<" .. type(value) .. ">\""
-    end
-end
-
-local function file_load(filename)
-    local file
-    if filename == nil then
-        file = io.stdin
-    else
-        local err
-        file, err = io.open(filename, "rb")
-        if file == nil then
-            error(("Unable to read '%s': %s"):format(filename, err))
-        end
-    end
-    local data = file:read("*a")
-
-    if filename ~= nil then
-        file:close()
-    end
-
-    if data == nil then
-        error("Failed to read " .. filename)
-    end
-
-    return data
-end
-
-local function file_save(filename, data)
-    local file
-    if filename == nil then
-        file = io.stdout
-    else
-        local err
-        file, err = io.open(filename, "wb")
-        if file == nil then
-            error(("Unable to write '%s': %s"):format(filename, err))
-        end
-    end
-    file:write(data)
-    if filename ~= nil then
-        file:close()
-    end
-end
-
-local function compare_values(val1, val2)
-    if is_one_of(val2) then
-        for _, option in ipairs(val2) do
-            if compare_values(val1, option) then
-                return true
-            end
-        end
-        return false
-    end
-
-    local type1 = type(val1)
-    local type2 = type(val2)
-    if type1 ~= type2 then
-        return false
-    end
-
-    -- Check for NaN
-    if type1 == "number" and val1 ~= val1 and val2 ~= val2 then
-        return true
-    end
-
-    if type1 ~= "table" then
-        return val1 == val2
-    end
-
-    -- check_keys stores all the keys that must be checked in val2
-    local check_keys = {}
-    for k, _ in pairs(val1) do
-        check_keys[k] = true
-    end
-
-    for k, v in pairs(val2) do
-        if not check_keys[k] then
-            return false
-        end
-
-        if not compare_values(val1[k], val2[k]) then
-            return false
-        end
-
-        check_keys[k] = nil
-    end
-    for k, _ in pairs(check_keys) do
-        -- Not the same if any keys from val1 were not found in val2
-        return false
-    end
-    return true
-end
-
-local test_count_pass = 0
-local test_count_total = 0
-
-local function run_test_summary()
-    return test_count_pass, test_count_total
-end
-
-local function run_test(testname, func, input, should_work, output)
-    local function status_line(name, status, value)
-        local statusmap = { [true] = ":success", [false] = ":error" }
-        if status ~= nil then
-            name = name .. statusmap[status]
-        end
-        print(("[%s] %s"):format(name, serialise_value(value, false)))
-    end
-
-    local result = {}
-    local tmp = { pcall(func, unpack(input)) }
-    local success = tmp[1]
-    for i = 2, maxn(tmp) do
-        result[i - 1] = tmp[i]
-    end
-
-    local correct = false
-    if success == should_work and compare_values(result, output) then
-        correct = true
-        test_count_pass = test_count_pass + 1
-    end
-    test_count_total = test_count_total + 1
-
-    local teststatus = { [true] = "PASS", [false] = "FAIL" }
-    print(("==> Test [%d] %s: %s"):format(test_count_total, testname,
-                                          teststatus[correct]))
-
-    status_line("Input", nil, input)
-    if not correct then
-        status_line("Expected", should_work, output)
-    end
-    status_line("Received", success, result)
-    print()
-
-    return correct, result
-end
-
-local function run_test_group(tests)
-    local function run_helper(name, func, input)
-        if type(name) == "string" and #name > 0 then
-            print("==> " .. name)
-        end
-        -- Not a protected call, these functions should never generate errors.
-        func(unpack(input or {}))
-        print()
-    end
-
-    for _, v in ipairs(tests) do
-        -- Run the helper if "should_work" is missing
-        if v[4] == nil then
-            run_helper(unpack(v))
-        else
-            run_test(unpack(v))
-        end
-    end
-end
-
--- Run a Lua script in a separate environment
-local function run_script(script, env)
-    local env = env or {}
-    local func
-
-    -- Use setfenv() if it exists, otherwise assume Lua 5.2 load() exists
-    if _G.setfenv then
-        func = loadstring(script)
-        if func then
-            setfenv(func, env)
-        end
-    else
-        func = load(script, nil, nil, env)
-    end
-
-    if func == nil then
-            error("Invalid syntax.")
-    end
-    func()
-
-    return env
-end
-
--- Export functions
-return {
-    serialise_value = serialise_value,
-    file_load = file_load,
-    file_save = file_save,
-    compare_values = compare_values,
-    run_test_summary = run_test_summary,
-    run_test = run_test,
-    run_test_group = run_test_group,
-    run_script = run_script,
-    one_of = one_of
-}
-
--- vi:ai et sw=4 ts=4:
diff --git a/external/json/lua/json2lua.lua b/external/json/lua/json2lua.lua
deleted file mode 100755
index 014416d..0000000
--- a/external/json/lua/json2lua.lua
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/usr/bin/env lua
-
--- usage: json2lua.lua [json_file]
---
--- Eg:
--- echo '[ "testing" ]' | ./json2lua.lua
--- ./json2lua.lua test.json
-
-local json = require "cjson"
-local util = require "cjson.util"
-
-local json_text = util.file_load(arg[1])
-local t = json.decode(json_text)
-print(util.serialise_value(t))
diff --git a/external/json/lua/lua2json.lua b/external/json/lua/lua2json.lua
deleted file mode 100755
index aee8869..0000000
--- a/external/json/lua/lua2json.lua
+++ /dev/null
@@ -1,20 +0,0 @@
-#!/usr/bin/env lua
-
--- usage: lua2json.lua [lua_file]
---
--- Eg:
--- echo '{ "testing" }' | ./lua2json.lua
--- ./lua2json.lua test.lua
-
-local json = require "cjson"
-local util = require "cjson.util"
-
-local env = {
-    json = { null = json.null },
-    null = json.null
-}
-
-local t = util.run_script("data = " .. util.file_load(arg[1]), env)
-print(json.encode(t.data))
-
--- vi:ai et sw=4 ts=4: