add feature where you can listen to the favorites of a user

this is bind to the f key
it asks for a username,
if you never navigated to a user before

this changes the internals of TrackCollection,
to allow more input streams. other then recent and user
track position seeking
Merge pull request #31 from timothybone/master

Track Position Seeking
track position seeking
list favorites of a user, bound to f key