util.startup: Provide a common Lua 5.3+ math.type() for Lua 5.2
Code deduplication
For full information on our dependencies, version requirements, and
where to find them, see https://prosody.im/doc/depends
If you have luarocks available on your platform, install the following:
- luaexpat
- luasocket
- luafilesystem
- luasec