Implemented keyboard input.
Removed old unused files.
Updated scene, model and mesh classes.
Added math_ext as math api and std as ext api for scripts.

I'm not maintaining boost and eigen configurations atm.
Added missing module dependency for game module.
Fixed gitignore to ignore all build folders except "premake".
Added pm_td project.

This project is "the game".
Removed unused class SpriteSheet.
Fixed some warnings regarding lacking assignment operators.
Added MeshManager to graphics system.
Added missing change to TestWindow.cpp.