Service Maintenance
- OfficialFM: Added offline support
Moved Test urls from the Autoload file, to the correct test service
Service Maintenance
- PollDaddy: Added partial offline support.
- PollEverywhere: It turns out the html response from the provider is wrong. I cannot do anything about it though
- Sapo: Added offline support
- Screenr: Added Offline support
- Scribd: Added Offline support
- Sketchfab: added Offline support
- Ted: Added offline support
- Urtak: Added html key to the response
- Viddler: Minor corrections
- YFrog: Added html key to the response
Added option to allow offline responses to the Formatter.
- Added relevant tests
- Remove empty placeholders from the formatter result
Check for error keys on provider response
- Some providers give 200 OK http headers, even when they have errors or
  the response is incorrect. So Its important to check for keys like 'error'
  or 'errors'.
- Github's oembed service seems to be offline for some time now, the fake
  response is almost identical to the original so I'm not going to ditch
  the service for now.
- Added Spotify tests, even though I cannot test it nor have I valid/invalid
  urls to test it.