feature: looped recording

[runlow]

Not sure if this is already implemented and I haven't figured out how to do it yet.

It would be nice for the looping to optionally also to work while recording so that new channels can be recorded (or recorded over) on the fly - almost like a continuous performance. This is in contrast to the default way in which you have to stop the recording when it goes over your loop, rewind, and record again.

Here's an example of what I mean (would like to be able to do something like this): https://www.youtube.com/watch?v=5JYSWHjIU_Q