- Split painting for current frame and onion skinning
- Introduce blitRect for updating only the dirty portion of the frame
- Optimization: Only do an expensive fill when the size changes, otherwise rely on the blitRect to clear the dirty portion.

Aside from cleaning up various extra update methods that are no longer necessary, I've made a minor change in vectorImage, in order to get it's correct dirty region.

This was a necessary change in order to calculate the correct bounds that wouldn't draw artifacts.

This also fixes some inconsistency in the CanvasPainter that I couldn't make sense of..

Although i don't like that this exists in our painter, I believe we added it because for some reason the image hasn't been loaded yet, so let's leave it for now... ideally though i've really like to get rid of such weird mutable things that has little to do with painting.

…improvements-v2

Additionally this will fix some artifacts when smudging

- Note that VectorImage hasn't been implemented yet.

…mprovements-v2

This was causing the gaps to be drawn between the tiled buffer tiles in some cases... particularly when erasing and you had zoomed in or out.

…nts-v2

Fix ScribbleArea repaint when tiled buffer does not cover update rect

…ng-improvements-v2-camera

…ng-improvements-v2-camera

…ng-improvements-v2-camera

…ng-improvements-v2-camera

in order to support HDPI properly