Added pomf.se WebM and MP4 support

Added support for WebM and MP4 video formats for the website http://pomf.se

Request from Reddit: http://redd.it/293ee6
Shall I try and figure out a way to do the detection system then? I think it would work fine using the [`canPlayType`](http://msdn.microsoft.com/en-us/library/ie/ff975191(v=vs.85).aspx) function and only show the inline video player when it returns `probably`.

And yes, the pomf.se links are direct links.