Bug 910316 - [e.me] Everything.me features in enhanced branch for Firefox OS 1.2 r=crdlc

https://bugzilla.mozilla.org/show_bug.cgi?id=910316

This is to group all features implemented in everything.me branch to start a review and land them on master branch. And this is the whole list:
* Homescreen:
  * Convert landing page into a normal grid page (can contain apps)
  * New grid icon type - Collection
  * Enable dragging a grid icon (app/bookmark) onto a Collection
  * Enable grid-wide banner
  * Remove opacity change on panning
* Collection:
  * Open/close animation
  * Static apps edit mode
  * Long tap Cloud app to pin to top
* Evme search results:
  * Improve Installed app categorization logic
  * Add Marketplace download suggestions
  * Remove result click animation (minor change)
  * Remove new result animation (minor change)