Only loop through array indices and error checking
added spine atlas file loader
removed trailing comma
added approach for trim in atlas loader
added atlas loader in gruntfile
fixed realSize property names
fix doc header
Merge remote-tracking branch 'upstream/dev' into dev
atlas loader support more than one spritesheet file
Add AMD export, fixes #267
Merge pull request #187 from johnste/dev

Use proper array iteration
change conditional, fixes #187 conditional
Stage now interactive by default
Fixed canvas interaction bug

Fixed bug where invisible interactive element it still active even if
invisible
Use correct IE ajax
minor optimizations in bitmap font loader
Only draw if frame has width and height (fixes IE index issues)
fix font not being served as text/xml on dev server (causes IE explosion)
cherry-pick canvas fixes from 9eaa024
cherry-pick sprite fixes from d533d89