Enable deletion of local-only media

- Fixed remote status accuracy for failed uploads. Assign new media to 'Local'

- Assign mediaID to new uploads (current timestamp in seconds since Epoch). Use remoteURL to determine if media was every uploaded instead.
Progress/status updates for cell and title accuracy

- Media browser cell reflects accurate status

- Fixed intermittent observer-related crashes

- Adjust disabling the upload button if user doesn't have permission to view media library (from changes to upload button earlier) for iOS 6 and 7.

- Fixed bug where if an upload failed, the user interface was still locked during delete.