Keep unmuted volume values if volume muted

If a volume control was muted, the hidden 'unmute volume' value was not
saved to the configuration, meaning that if you exit while muted then
restart, it would unmute to 100% each time, causing annoyance for some
users.
Merge branch 'master' of https://github.com/jp9000/OBS into obsvce
Attempt to improve CBR encoding performance for VCE1.

The behavior of the CBR rate control method seems to be secondary to
other encoder parameters.  These setting have given me somewhat
consistent bitrates in preview.  Twitch reports excellent stream
quality, but it is visually quite disappointing at this point.
Stats. "Manual" keyframes.
Merge branch 'obsvce' of https://github.com/janeuner/OBS into obsvce

Conflicts:
	ObsVCE/src/ObsVCE.cpp