Android: Feed/Folder Sync Fixes

Fixed a nubmer of bugs related to feed/folder syncing:

* ensure that part two of the 2-step auto sync finishes despite feeds with no stories
* actually make the Saved Stories counter update after the first sync
* correct the All Stories counter for users with deleted feeds (#284)
* reflect changes to feed and folder naming and structure (#256)

In solving the latter two items, I replaced some complex premature optimization with a comparatively simple DB wipe and batch-load.  On a couple of my devices, this also significantly sped up sync operations!