Must call addHeaderView before calling setListAdapter on older Android versions
Making layouts/callbacks used in Artist Activity more generic

I plan to re-use a lot of the layouts for the torrent group view. It'll basically be the same view but with the album art and torrent information being shown instead
Adding basic Torrent Group view and shortcutting to test it

It's an identical themed layout to the Artist Activity, a big header image of the album art and a list of the all the torrents. Later the torrents will be grouped up by release to distinguish deluxe/special editions whatever. I need to double check that the ordering we get back for these is always correct though since it seems the API just throws us one huge list of torrents. If they aren't grouped by their release type and in chronological order we'll need to do the sorting/grouping on our end, or add a function to do it in WhatAPI