Make Stroke be composed of chunks, to simplify drawing model
Since all Stroke.Chunk instances have only two spars, simplify data structure and compact serialization format
Add automatic version # script
Dirty-rect tracking to fix performance issues when drawing.

- now it's 100% playable on an iPad mini! WOO!
When showing gallery details, blank image cell on reuse since it can take a moment to render the match
Make match view controller animation transitions support user interaction
Merge branch 'chunked-drawing-experiment'
Delete a couple files that shouldn't have made it into GIT
Add parallax motion effect to the save-to-gallery dialog view controller