Respect that out y-axis goes down in rotation code.
Fix wrong argument indices in graphcis.Image.setPixel and graphics.Image.getPixel.
Rename rotation constants to 'cw' and 'ccw' for brevity and consistency.
Rename 'rotate' parameter to 'angle' which makes more sense.
Make blend mode a parameter instead of a state.
Remove unused field in the image class.
Change license to MIT.