New level parser

Known issues:
* TerrainLevel for some reason doesn't work
* %lvl% is not yet implemented everywhere because of hardcoded directories in functions
Don't use physfs in saving code for now

This requires too much refactoring and we want to release 0.1.5 soon.
We'll need to rewrite saving/loading code to fully implement new level parser anyway.
Userlevel listing
Merge branch 'dev-physfs' into dev-physfs-levels
Fixed some warnings

Removed unused variables and fixed signed/unsigned comparation warnings
Removed more unused variables
Fixed TerrainLevel bug
Moved effect??.png textures and made pos= in GroundSpot optional
Updated level check script
Made proxyDistance optional
Updated data submodule