dvdplayer: drop last packet duration

It's no longer used for anything usefull. The timeout logic
will work just as well with just being after audio runs dry.
dvdplayer: drop pointless temporary variable
dvdplayer: remove duplicate log lines by printing parameter
coreaudio: make sure flush request is served even when paused

Core doesn't callg GetFrames when paused, causing it not to serve
the request.

This speeds up seeks but a lot on osx
dvdplayer: wait on message queue in fast forward instead of blocking waits

This speeds up dvdplayer audio's reaction time to playback state
when going from a fast fordward state to normal state.

We keep in sync by only requesting new frames when clock says we need
one.
dvdplayer: drop unused IsMasterClock logic

This logic got replaced by: e1bc8f1414c0f29860d9c36575f4c2227b59a322