the loop delay in generating and playing signals should be more accurate

[robertoostenveld]

right now it is based on a short-term estimate. There is still some code evaluated which is not part of that estimate. The consequence is that the loop is slightly (few ms) too slow.

This relates to generatesignal, playback and playbackctrl, but possibly also the synthesizer module.

[robertoostenveld]

I have implemented the new smoothing and calibration modules with an improved timing in the main loop (not using a simple delay, but adapting it to the execution speed)

[robertoostenveld]

This is something that could now be implemented consistently in loop_forever