Fix for glitchy/popping/skipping audio

[elvisish]

I've spent a while trying to figure out how to stop skipping, popping, glitchy sounds with scummvm and I think this combination should help most occurances:

• Turn on VSync (if you have a monitor with GSync or FreeSync it should allow vsync to be turned on without the laggy mouse feel)
• Add audio_buffer_size=8192 to scummvm.ini (it'll disappear when you run scummvm, but it's still there it's just moved below subtitles)
• Run with compatibility mode for Windows Vista (7 and 8 might also work)
• Disable fullscreen optimizations
• Try your soundcard at 44100khz and/or set scummvm's output_rate to the same.

I'll add more to this list if I come up with any more solutions, but hopefully that'll be useful for anyone who's having any problems.