* introduce GestureDetector to TextView
* completely remove link click functionality from
LinkMovementMethod (the interface does not state it
provides click functionality)
* intercept onSingleTapConfirmed and trigger onClick on the
link if it exists (simplified duplicated functionality)
* renamed a bunch of LinkMovementMethod variables because
eyes hurt
Bug: 23692690
Change-Id: Idaf3f3391328207f42521235fb5deb1a11c66aaa