Cleaned up OpenGL initialization

Cleaned up OpenGL initialization
    src/ui/GraphicsManager.cpp
Added SDL_GetError logging in main loop

Added SDL_GetError logging in main loop
    src/core/MainManager.cpp
Updated GLM version, and added BULLET library

Updated GLM version, and added BULLET library
    SConstruct
    src/SConscript
    src/SConscript_tests
Minor fix: Hid static member variables

Minor fix: Hid static member variables
    src/math/Random.cpp   (+)
    src/math/Random.h
Added length & normalize functions to Pointf, Sizef

Added length & normalize functions to Pointf, Sizef
    src/math/Pointf.cpp
    src/math/Pointf.h
    src/math/Sizef.cpp
    src/math/Sizef.h
    src/math/TestPointf.h
    src/math/TestSizef.h
Added constants to MathUtil

Added constants to MathUtil
    src/math/MathUtil.cpp
    src/math/MathUtil.h
    src/math/TestMathUtil.h
Added floating point rectangle class Rectf

Added floating point rectangle class Rectf
    src/math/Rectf.cpp   (+)
    src/math/Rectf.h     (+)
    src/math/TestRectf.h (+)
Added accepted types to Log output stream

Added accepted types to Log output stream
    src/util/Log.h
    src/util/LogManager.cpp
Added MathUtil function for overlapping rectangles.

Added MathUtil function for detecting overlapping rectangles.
    src/math/MathUtil.cpp
    src/math/MathUtil.h
    src/math/TestMathUtil.h
Added shader program creation using shader list

Added shader program creation using shader list
    src/ui/ShaderProgram.cpp
    src/ui/ShaderProgram.h
Added basic physics engine frame

Added basic physics engine frame
    src/core/MainManager.cpp
    src/core/MainManager.h
    src/model/PhysicsWorld.cpp (+)
    src/model/PhysicsWorld.h   (+)
Added operators <, ==, != to Asset

Added operators <, ==, != to Asset
    src/util/Asset.h
    src/util/TestAsset.h
Cleanup: Renamed ObjMesh->Mesh, and SDL RAII objs

Cleanup: Renamed ObjMesh->Mesh, and SDL RAII objs
    src/ui/GraphicsManager.h
    src/ui/ObjMesh.cpp -> src/ui/Mesh.cpp
    src/ui/ObjMesh.h   -> src/ui/Mesh.h
    src/ui/MeshRender.h
    src/ui/SDL.h
    src/ui/SDL_mixer.h
    src/ui/SDL_ttf.h
    src/ui/Surface.cpp
    src/ui/Surface.h
    src/util/RAIIhelper.h
    src/wip/DeferredRenderer.h
    src/wip/ObjRenderer.h
    src/wip/ToTextureRenderer.h