BrowseFragment: Unset on stop prior to stop as it may not exist afterward.
Fragments: Cleanup all the refreshFastScrollStyle methods.
PlaylistFragment: Small fix to dd8a5c2 (thanks @Hurzl).
MPDroid: Fix improper refactored nesting from commit 66ba6a6.

This commit also removes getKeyCode() when keycode is already available as a
parameter. Thanks again goes out to @Hurzl.
Merge pull request #555 from avuton/next

Fixes for last PR, tiny cleanup.
allow PlaylistFragment to be subclassed
Merge pull request #556 from hurzl/genre

allow PlaylistFragment to be subclassed