Merge pull request #677 from loiccouturier/master

Fix avatar manager. Fix fatal error in workflow. Enhance NotificationCenter. Fix #507
Spellchecking
US Localization
Fixed JavaScript object creation for Main menu.
Fixed strange behaviour with z-indexes and 3D transformations in Main menu.
Removed Twitter Bootstrap's "panel" component for <rbs-document-list/>.
Changed main background color to white.
Refactoring of Asides management. Still have to rewrite some templates for all plugins...
New layout: left sidebar has been removed and each plugin can have a sidebar (or not), declared in every plugin view.
Upgraded AngularJS to 1.2.3
Fixed SelectSession.
New layout: left sidebar has been removed and each plugin can have a sidebar (or not), declared in every plugin view.
Added link to view the PageTemplates from the Theme editor.
New layout: left sidebar has been removed and each plugin can have a sidebar (or not), declared in every plugin view.
Removed fake data on the dashboard screen and added a welcome message.
New layout: left sidebar has been removed and each plugin can have a sidebar (or not), declared in every plugin view.
Merge pull request #678 from fredericbonjour/Admin

New layout: left sidebar has been removed and each plugin can have a sidebar (or not), declared in its views.
Fix NotificationCenter