server patch configurable at settingstypes.txt

[mckaygerhard]

due several differences on dependences requirementes the server path are always diiferent from distributions.. so i guess we can added a string configurable with settingstype.txt and also in config file to provide the search path for lua libs, i will send a PR that will solve isues like https://github.com/minetest-mods/irc/issues/54 https://github.com/minetest-mods/irc/issues/66 and some olders