Add/remove points from the curve

[siegmour]

Currently there are 3 points to control the curve with. It would be very nice if you can add/remove more points to that.

[integralfx]

I considered this but IMO, 3 points is enough for a curve. 1 for idle, 1 for load and 1 to adjust the transition between idle and load.

I'll probably end up adding it after 1.0.0.