Prevent audio too far from expected timing

Audio that goes below the minimum expecting timing (current time -
buffering time) is automatically removed.  However, delayed audio is not
removed regardless of its delay.  This puts a hard cap of 6 seconds from
current time that the maximum delay audio can have.  This will also
prevent the circular buffer from dynamically growing too large.
Remove audio/video sync reference counter

This is actually unnecessary now that there's a hard limit on the
maximum offset in which audio can be inserted.

This also assumes too much about the audio; it assumes audio is always
on, where as with some devices (such as the elgato) audio is not on
until the stream starts, and when the video has already incremented the
counter.
win-dshow: Swap UYVY and YVYU formats

These values were erroneously using their opposing types for the source
frame format.