Reset windup

http://brettbeauregard.com/blog/2011/04/improving-the-beginner%E2%80%99s-pid-reset-windup/

This prevents the controller from giving an output value that is out of range and stops the integral term from "winding up."
> What do you think about a test that trips the panic and uses recover()?

Might be overkill, but I certainly won't complain if you want to write it :smile: