Issue #205: set layer to hardware during animation
Issue #207: upgrade to support library v12

This has some ViewPager fixes. However, I'm now going to try using a
ViewPager inside of a fragment which supposedly worked in V11 to
address some janky menu item issues due to using the split action bar.
Issue #207: replace ThingPager with ThingFragment

This is the beginning of a long attempt to put a ViewPager inside of a
Fragment and eventually use a single Loader to get at a thing's metadata
conveniently.
Issue #207: transition to support v4 classes

getChildFragmentManager is only available in recent releases, so there
is no choice but to migrate to the v4 support library which has it.
So convert everything possible to use v4 Fragments and Loaders.
Since you have to extend FragmentActivity, AccountAuthenticatorActivity
no longer works at the moment. I'm sure there were other things I broke
too...