Don't trigger model tag change events more than needed.
Only apply options to canvas context when necessary.
Don't re-calculate document size when tags are changed.
gulp
Fix bug in text selection logic.
gulp
Speed things up:
- Cache measure text calls
- Don't select pasted text immediatley after pasting it.  Especially
  since it was then just deselecting it.
gulp
Add rows_added event
gulp
Merge pull request #20 from jdfreder/handle-a-lot

Handle a large amount of text