Print version of linked Lua library at startup.
Removed superfluous string copy code.

I didn't know that strcpy/strncpy already assures, that the last byte in
destination is always a \0 byte.
Began integration PhysFS.
Removed some redundancies from configuration module.
Renamed FileSystem module to PhysFS.
Fixed Lua version reporting.
Merge branch 'master' into feature/physfs-integration

Conflicts:
	engine/Controls.cpp
	engine/ModelWorld.cpp
Implemented basic PhysFS module.
Added Lua module for PhysFS.
Updated README.
Replaced libPNG dependency with stb_image.
Removed some code smells in Texture.cpp.
Merge branch 'master' into feature/physfs-integration
Refactored image module to use PhysFS.
Refactored shader module to use PhysFS.
Moved LoadFile utility to PhysFS module.
Refactored Lua module to use PhysFS.
Enhanced PhysFS integration.
Moved compilation of stb_image out of engine.
Implemented PhysFS compatible require()