Added cheap lazy templates + logic to switch between setting controllers
Merge branch 'master' into feature-gif-export-panel
Merge branch 'master' into feature-gif-export-panel
Merge branch 'master' into feature-gif-export-panel
Gif export panel first draft
Issue 24 : Layers

!! NOT STABLE !!
Initial implementation. No UI update yet.
Check js/model/Piskel.js and js/model/Layer.js for an overview of the new
API.

Piskels can be saved on the existing service.

Previous piskels cannot be loaded. This should be fixed soon.
First layer UI. Just functional, UX far from ideal
Layers container style update
Layers : add layer icon. Position buttons on top of list. Fix name generation issue
Arrow icons update
Clear layers canvas before redraw
Fix jscolor : add jscolor.install to Palette Controller init sequence. Fix layer canvas update on DPI change
Layers : fix : Set button height to 24px
Merge branch 'master' into feature-gif-export-panel
Dev environment : closure compiler + jshint update

Fixed error raised by closure compiler
Added es3 option to jshint (detect trailing commas)
Added curly option to jshint (missing curly braces for if/for blocks)
Removed trailing whitespaces (not enforced through jshint though)
Layers : FRAMESHEET_RESET -> PISKEL_RESET

Framesheet no longer exists.
Layers : Deleted js/model/Framesheet.js

No longer used
Dev environment : Remove globals
Dev environment : JSHint will raise error if trailing whitespace
Layers:Review:Only one selector per line