Don't initialise the ROM memory at startup, since a ROM needs to be loaded into it anyway. According to BassAceGold's timings, this should save 179 milliseconds.
Hook fast-forward into Settings.TurboSkipFrames.
Make the audio timing more precise.

* Fake out the buffer timing by sending a buffer full of silence when returning from pause. Reduces crackling introduced by the next point.
* Send buffers only once every 23.22 milliseconds, not up to four buffers at once (92.88 milliseconds) and randomly thereafter. Reduces note-length jumpiness.
* Audio may have trouble catching up if external jitter reaches 11.61 milliseconds. That happens if Mode 7 images or filtered modes take a long time to render, or if chips take a long time to execute.
While killing time between frames, process audio instead of doing nothing. Also correctly fill the buffer with silence when returning from pause. This reduces or eliminates crackling.

The emulator kills time in two circumstances:
* In automatic frameskip mode, without fast forwarding, the emulator kills time if it rendered a frame early.
* In manual frameskip mode, without fast forwarding, the emulator kills time to wait for the next rendered frame.
Revert the reversed stereo mixing loop. This makes it more consistent with mainline Snes9x, in case of merges from 1.53. It also didn't help much, given that the problem was trying to push 92 milliseconds of audio inside 20 milliseconds of time.

This reverts commit 2b715684087675747df7cb8995695936f20c782b.
Add an option that controls which element should be more fluid, per game: video or audio.

This makes most games playable, but the player can choose to get fluid audio instead of fluid video in sound-test modes or games with epic soundtracks.
Release 1.25.