Add the FasttrackBadgeWidget.

This widget is an extension of ImageView that takes care of the standard
fasttrack badging and on-click behavior. It should be used in any
applications that display contact photos.

This view's name will have to be changed before release, and will be
kept private until the name change is made. At that point the view will
be made public api.

Change-Id: I4704e0e979466929ad7b2ef11911681a5028b4a7