Added ability to play archived videos (past broadcasts)

Allows playing of past broadcasts and saved video highlights.

The followers list will now show Live channels at the top, and all the channels you follow underneath. Selecting a channel will give you 2 options, past broadcasts and video highlights.

Twitch splits archived videos into 30 minute segments, so I just got a list of all the segments then created a playlist with them using "xbmc.PlayList()"

I tried to stick to the code layout you use, but it still might need some refactoring.