TinyGL 2D Blitting API

This PR contains an implementation of a common blitting API for TinyGL, the API supports the following features:
- Alpha/Additive/Subtractive Blending
- Fast Binary Transparency
- Sprite Tinting
- Rotation
- Scaling
this line is ugly, when I look at I'm not sure what I see: "new Graphics::BlitImage*[bitmap->_numImages];"