MPDroid: Remove redundant casts.
dmix: Spelling corrections.
MPD: Create string array of correct size when using toArray().

When toArray() is called on a Collection object with a zero-length array
argument, the toArray() method has to construct a new array of the right
size using reflection, which is significantly expensive.
dmix: Simplify redundant boolean conditionals.
MPDroid: Resource cleanup.
dmix: Fix a bunch of docbook errors.
dmix: Remove redundant local variables.
JMPDComm: Remove and document unused conditionals.
dmix: Remove redundant boolean conditionals.
dmix: Remove redundant initializers.
dmix: Remove unused imports.