Add SharingSupport activity - use ShareCompat.IntentBuilder to produce
sharing intents for menu item sharing, text only, single stream, and
multiple stream.
Add SharingReceiverSupport - receive text/plain content as text only,
single stream, and multiple stream.
Add SharingSupportProvider - simple filesystem-based read-only
ContentProvider for providing a data stream.
Change-Id: I7e69a80984c0c5a8d93663f928f644d55c92350d
