Language Updated

1. You can now finally add your own language files to the game.
2. You can set the default language for the server to whichever file you want.
3. Players can choose personal language setting as well with /language set en_us
4. Players can see all language option with /language list
5. Players can come back to default server with /language reset
6. Internally, we switched from server jar as source to maven repository.

Side note

Your contribution to add localisation of language to official mod is welcome on the github. Last update /vanish command was changed to /staffvanish and was missed in update notes.