Bug 974736 - Add icon to title bar of Sponsored Tiles [r=adw]
Also fixes bug 976638 by moving controls.png to the shared directory.
Add an always visible sponsored icon for tiles that are type=sponsored. Also add ignorehover to the cell to prevent styling when pointing at the sponsored icon that happens to be a child of the cell.
Bug 975210 - Augment Site._render logic to allow for Sponsored Tiles images & text [r=adw]
For type={affiliate,organic,sponsored} tiles, show the appropriate imageURISpec instead of thumbnail.
Bug 974745 - Create click event on Sponsored Tiles to show explanation panel [r=adw]
Have the page know how to show a panel on a sponsored icon click.