Contains important bug fix.

Changes
Fix: Pixel perfect drawing removed pixels when crossing lines.

Fix: Mouse wheel action for zooming now only applied when mouse pointer is on canvas.

Fix: Middle mouse button executing canvas mover sometime drew on canvas instead of moving it

Fix: frames sometimes not loaded correctly. Some (mostly larger) frames might not load correctly due to a compression decoding fault.

Added auto scrolling mechanism to toolbox for when the height does not fit on screen

Brush transformation tools now allow adding frames without stopping transformation