Add check if season thumbs exists before download
Return only True if all season_thumbs are saved
Handle failed downloads

Detect and track failed nzbs and don't re-download them.
Properly handle multi-episode NZBs
Improve failed download handling

Let postProcessor handle finding release_name, and update history and
set episodes to wanted in the same place.
Create a separate failed database

Also added a web UI
Merge remote-tracking branch 'ms/development' into failed-download-handling
Fix some issues

Fix error when nzbName is None
Fix error in postProcessor when self.file_name has periods but no
extension
Enhancement :: Show listings : Enable choice of sorting show lists by articles (the, a/an).
Enhancement :: Config - Notifier - Plex : Expanded the functionality of the test button for Plex notifier to include testing server connection.
Bugfix :: Config - Notifier - Plex : Connection to non-existent host never timed out.
Cosmetic :: Config - Notifier - Plex : Updated text on test button to reflect changes.
Cosmetic :: manage_episodeStatuses.tmpl : Restructured layout of "Episode Status Management" web page to decrease chance of accidental status change.
Enhancement :: manage_episodeStatuses.tmpl : Added unknown quality downloads to list of manageable episodes.
Enhancement :: Mass Edit Logging : Reduced noise by only logging flatten_folder status if altered.
Bandage :: Backlog search_queu : Rough bandage to prevent exception when curResult list contains a None value. (Gotta find the actual cause later)
Don't check for failed download on torrents
Merge remote-tracking branch 'ms/development' into failed-download-handling

Conflicts:
	sickbeard/postProcessor.py
Cosmetic :: Search - Logging : Added name of nzb snatched to log message.
Cosmetic :: Search - Logging : Add log message to indicate when search completed for TV show season.