Write custom events mechanism that avoid the frequent context switches in Backbone events

It's more bareboned but faster.. Also replace all occurences of .bind with .on, to make the distinction between Function.prototype.bind() easier.
Stats
Tests
Don't render hidden objects
Fix
Caching
Hack add text
Dirty hack
Avoid unnecessary null transforms
Canvas drawing loop improvements

Use plain for loop, use direct _x, _y properties where possible.
Add support for image smoothing param

Set it to false when woking with pixel art. False might lead to better performance, since it would use cheaper interpolation algorithms. It might not make a big difference on GPU backed canvases.
Improve get bounding client rect

Remove forEach, direct accessors
Add shallow parameter to group boundingClientRect
Only set opacity flag if there is an actual difference
Fix array
This whitespace annoys me when building and diffing