Fix language selection issues

Make the Profiles dropdown have focus instead, so accidental keypresses
don't change the current language. Also make cancel cancel the language
setting and make user confirm changing it when switching settings pages.
Video capture device properties dialog fixes

Fix the properties dialog so it doesn't needlessly refresh the source if
no settings have been changed.
Add option to preserve DirectShow source size

For when you want to make sure that your DirectShow capture source stays
in place and the same size even if you change the input resolution.
Skip transition on non-global capture device source

Skip the transition if there's a non-global capture device source in the
next scene. Mainly a fix to make device capture sources using the same
device as one in the previous scene not show up blank after switching.
Fixed typo in QSV encoder height check
Extend QSV resolution check for Ivy Bridge
Improve DTS handling for QSV encoder

Improves audio delay/sync
Lock scene mutex when reconfiguring global sources
Fixed frame_ticks calculation and added bounds check for init_pts