Category change in Bugzilla

[Bart Cerneels]

We currently have the PlaylistBrowser component in bugzilla. To more
accurately reflect the way it looks in 2.2-GIT we split this up into
the individual content categories under playlists. This will make it
easier for the reporters to select the correct category.

So here is what I propose:
- We rename PlaylistBrowser to SavedPlaylist and move all existing
bugs along with it.
- We add a more general "Content" component for bugs relating to the
browser itself and wishes for new categories (like Smart Playlists).
- We already have Podcasts and DynamicPlaylists keep using them.

If Dynamic is going to be the way to implement the smart playlist
functionality (?) move those wishes to that component.

We should do the same for the standard services as well.

Bart