MPDroid: Remove StringUtils.

Very basic and duplicate utilities resided in StringUtils.
MPDroid: Remove unused classes.
AlbumParcelable: Fix write ordering.

This fixes a regression from 162259d.
dmix: Reformat the entire project.

This has been very slow going class by class, go ahead and reformat the remainder.
dmix: Unify field naming.
dmix: Fix most code style/javadoc warnings.
dmix: Use static when available.
MPDroid: Use explicit isEmpty().
dmix: Fix StringBuilder and single character warnings.
dmix: Fix object comparison warnings.
ArrayAdapter: Avoid parameter modification.
dmix: Fix many name convention warnings.
StreamsFragment: Remove a couple of redundant variables.
dmix: Weaken types as possible.
MPDOutput: Use the response parser, make immutable.
MPDConnection: Before connecting, innerdisconnect if socket is not null.
CoverInfo: Remove redundant methods.

These methods are duplicates of the AlbumInfo class it extends.
dmix: Add missing override annotations, make public abstract methods protected.
MPD: Remove ternary operators.
AboutActivity: Return at the end of the method.