Add new providers discovered via Embedly/WordPress and some good guesses..
Add new providers discovered via Embedly/WordPress and some good guesses..

This adds:

* flic.kr
* gist.github.com
* mobypicture / moby.to
* polldaddy,
* scribd.com
* slidesha.re
* speakerdesk
* yfrog

coleifer/micawber,coleifer/micawber