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.