Remove unused code: Bitmap::OpacityBlit, BitmapScreen::BlitScreenTiled
Rendering simplification, clean-up
Add, use new EffectsBlit: Tone, Zoom, Single Opacity
Merge HSLBlit into HueChangeBlit (sat, lum changes unused)
Remove unused TransformBlit overload
Merge BitmapScreen into Sprite
Merge pull request #372 from glynnc/master

More Bitmap-related clean-up