Feature request: audio speedup

[yuripetnys]

Hello. I use Aegisub a lot for spotting/timing and I could really use a function that speeds up the audio reproduction by a multiplier (1.5-2.0x). I did some tests by speeding up the video with ffmpeg and it did enhance my productivity, but scaling the subs back to normal messes up the keyframe alignment. Having it natively would fix the issue.

Thanks for updating Aegisub