* Substitute unread view for unseen view until unseen view is ready.
* Register as many views as possible async.
* Perform blocking, safe migrations before async registration of views.
* Add debug settings view for internal app stats.
* Show blocking overlay until async registration of database views is complete.
* Convert version migrations to use AppVersions.
// FREEBIE
- Tested on jailbroken phone that correct files are getting encrypted
- Fixes#557
- Stores image file extension
- Addresses issue with deletion of debug logs
- Preventing user to browse in app if not registered with TS server