created HierarchyListAdapter, BrowseFragment

recent is now incorporated into Browse

there is still some extraneous cruft to remove
convert FavoritesFragment to inherit from BrowseFragment

standardize some state hacks throughout
BrowseFragment now requests a data file

if the 'library' hasn't been loaded from the server, fire up a
JSONRequestTask and fetch it. Once fetched, process it on the UI
thread, updating the database accordingly. In tests, this is
a very short time. With the full size stop/tag library, this could
take quite a while.

Basically, it may have to be moved to a separate thread, then we
only have to worry about concurrent database access. For now, I'll
keep it simpler.

Also, went ahead and made WtaFragment implement Start/Stop progress
because all views now may need to show progress and errors.
cleaned up a tag in HierarchyListAdapter
removed unused imports, deleted RecentFragment
now updating the Library in the background

ListView methods/properties on HierarchyListAdapter have been
properly moved to a new type HierarchyListView
Merge branch 'hierarchy_view'