Re-add sorting to HomeFragment, except heavily improved. The major
improvement here is the addition of song sorting, which was a heavily
requested feature judging by #16. The setting does not save yet and
is not present in the detail fragments, but it is still a major
milestone for the new home ui.
Refactor styles again, this time trying to seperate the more
layout-specific attributes so that layouts become more re-usable.
This also updates the naming conventions of styles.
