starting palette implementation using creation wizard
Added color picker in create palette popup
Extracted ColorPicker code to dedicated widget package (noooooooo) ; Added basic palette creation mechanism (list colors + add color)
Palette creator can save palettes to local storage
fixed bug with hue slider capped to 255
Enhancement : Palette colors creation

- Added cancel button to create palette dialog
- Added escape/unescapeHtml methods to pskl.utils
- Escaping palette name now ...
- Removed outdated comment in app.js regarding appEngine token
- Added a call to destroy() during dialogClose of AbstractDlgCtrl
Moved PaletteService from pskl.service to piskel.service.palette
Enhancement : Palette color creator

- Added import button on create palette dialog
- implemented import from images
- missing limitation on color count when importing !!
- should remove button when editing existing palette
Enhancement : palette color creator

- Added import of GPL files
Enhancement : Color palettes

- Added clone feature when editing existing palette
- Added arrow up/down to increase decrease input values
- Paint.net palettes are supported
Feature : merge layers

Added feature to merge a layer with the layer below
Done at #jsconfeu2014 :)

New icon in icons : merge-icon.png
TODO : reorder the icons folder, it's waaaaaaay too messy !!
Enhancement : Layers merge

Added drawing test + fixed drawing test runner on Mac OS X
increased the timeout for Travis tests
Merge pull request #220 from juliandescottes/enhancement-layers-options

Enhancement layers options
select new palette after saving
Enhancement palettes :  Added download palette

- palettes can be downloaded as GPL palettes
- slightly tweaked the UI of hsl rgb picker
- switched preferred format of spectrum to hex
Homogeneize layout, drop palette
Split CreatePaletteControllers in ctrl + widget for colors list
Moved image import to worker
added FrameUtils unit tests