Refactor videos

* More extraction of common parts
* Add support for youtube
* Standardise the way you access video
* Simplify video code, and add faraday caching for vimeo
Make the caching not suck
Make searchisko normalisation a bit cleverer
Oops, wrong var name
Merge pull request #62 from pmuir/DEVELOPER-872-part-2

Developer 872 part 2