added support for outputting text on the screen (through Freetype); for now only characters 32-127; added basic shaders for text

updated texture formats to include a redchannel texture type that is used by the Text module
added support for temporary meshes through the RegisterOneFrameMesh function in Renderer (used by text, which updates every fram)
added support for creating resources from code in RM
added an OpenGL error-checking macro
added NextPowerOfTwo function in MathUtils.h
refactored some code
removed old font code