Stuff to make up for my hiatus:
Implemented EnumRenderMode! It's about time.
Refactored everything involving rendering to use EnumRenderMode.
If rendering is impossible, the screen is no longer cleared, and the display doesn't update.
Implemented a new Matrix constructor.
Implemented Quaternion; Not my work per se, but I did reformat it to work with the engine.
implemented more Vector methods. (I prefer C++ for typecasting =/)
Fixed a hilarious oversight on my part in PixelGrid.
Implemented more safety checks to RenderEngine.