Afterburner

Hello Overengineer1 You made a great job with this invaluable mod which is really helpful! I just have a little suggestion: the orbit circularization should be optional when MechJeb is present, for two reasons: 1) you may want to set up your own maneuver node (not necessarily a circularization node) at apoapsis. 2) in career mode you can embark MechJeb on your vessel before its maneuver planer is enabled. In this case, Gravity Turn applies full throttle to your —totally uncontrollable— rocket!