stepsize and delay should be made more consistent

[robertoostenveld]

I noticed that the calibration module is using stepsize in the ini, whereas other modules are using delay in the ini. There is also a difference in the code, which is either a simple pause or adjusted to the compute time.

[robertoostenveld]

recordcontrol is using the general/delay option in the way that the other modules are using the stepsize option.

plotcontrol is using the general/delay option in its own way.