Some fixes and changes

I've added the ability to disable sending watching API calls during seek events and when resuming a video.  It will still send watching calls every 10 minutes irregardless as usual.  The main purpose of this is for those who have slower connections to cut down on the number of times trakt.tv is hit.  Main example for this is if seeking through a movie, in 10 minute steps, to the end to scrobble it, and the user is on a slower connection where it consistantly takes 20+ seconds to get results from trakt.tv.

I've also fixed the progress dialog staying on screen during a manual sync (if enabled) when data from trakt or xbmc is invalid and it cancels itself.  Seems I forgot to close the progress dialog in these instances.

I've also fixed possible crashes in scrobbler, was using the wrong class for some calls, not sure how I missed them.

As usual, needs testing, and feedback welcome.

##Changelog
- Fix possible crashes in scrobbler.py
- Add ability to disable sending watched calls on seek and when resuming playback, this can cut down on wait times from the API, for example playing a movie and seeking to the end in 10 minute skips to scrobble it.  This would mainly benefit those who usually have long response times from trakt.tv
- Close progress dialog if results from trakt or xbmc are invalid, otherwise dialog stays on screen with no way to remove it