mpdviz 0.4.3 (new formula)

mpdviz is a terminal visualizer for the music player daemon (mpd).

This is a redo of my previous pull request.  Initially the formula was pointed at the git repository, now it points to the 0.4.3 release.  Test was removed because "mpdviz --help" exits with a non-0 status and there is no other easy way to test.