Fixed compile on OSX and Linux by using pkg-config for both and making
includes match the paths provided.  Also fixed a goofup from the
renaming cleanup that inadvertently changed BreakMusic as well and broke
it.  OSX now builds and runs fine with the QMediaPlayer backend.  It
will successfully compile the GStreamer backend, but the brew version is
missing too much stuff for it to work.  May work with a full GStreamer
install, but you'll need pitch from gst-plugins-bad for key changes.
Also level, rgvolume, playbin, volume, and autoaudiosink are required.
I'm not expert enough on OSX to resolve this quickly, but I have a
feeling it will work just fine if a good install of GStreamer (1.0+) is
present and built against.