ZENGINE: Add method for getting a pointer to a Control
ZENGINE: Implement AnimationControl

This handles playing animations asyncronously over numerous frames
ZENGINE: Implement ActionPreloadAnimation::execute()
ZENGINE: Implement ActionPlayPreloadAnimation
ZENGINE: Stop avi playback once the animation is finished
ZENGINE: Create method for rendering to the working window with binary alpha
ZENGINE: Create method for getting the RenderManager backbuffer
ZENGINE: Save a thumbnail of the RenderManager backbuffer instead of the actual screen

This prevents things like the GMM being in the thumbnail
ZENGINE: Create class for rendering TrueType fonts
ZENGINE: Create method for converting image space to working window space
ZENGINE: Create method for clipping a rect to the working window
ZENGINE: Create method for transposing a surface
ZENGINE: Let Rlf animations output Surfaces instead of uint16 arrays
ZENGINE: Clip animations to the working window
ZENGINE: Add a debug assert to make sure we're not trying to render ouside the working window
ZENGINE: Update LeverControl to use the new RlfAnimation outputs
ZENGINE: Add comments to AnimationControl::process()
ZENGINE: Cache animation frames so they can be re-rendered when the background moves
ZENGINE: Remove extraneous methods from TrueTypeFont
ZENGINE: Use default dpi for font