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
Update data/interfaces/default/comingEpisodes.tmpl

Prevent the destination url to trace back location of sickbeard website with HTTP_REFERER headers. 
With this change the website thetvdb will not be able to trace back the sickbeard location because HTTP_REFERER will be set to dereferer.org. 
Merge remote-tracking branch 'ms/development' into development-custom
Merge remote-tracking branch 'ms/development' into development-custom
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
Merge branch 'failed-download-handling' into development-custom
Merge remote-tracking branch 'ms/development' into development-custom

Conflicts:
	sickbeard/postProcessor.py
Merge remote-tracking branch 'ms/development' into development-custom
Merge remote-tracking branch 'ms/development' into development-custom
Don't check for failed download on torrents
Merge remote-tracking branch 'ms/development' into development-custom
Merge branch 'failed-download-handling' into development-custom
Merge remote-tracking branch 'ms/development' into failed-download-handling

Conflicts:
	sickbeard/postProcessor.py
Merge remote-tracking branch 'ms/development' into development-custom
Merge remote-tracking branch 'ms/development' into failed-download-handling
Small style change

Explicit unicode for logger