Changed the fuelflow simulation to not stage if the new stage does not detach any parts and only adds new engines when there are already engine running.
This is to address a situation that is most obvious if you have an ion probe with seperatons attached to be used as breaking rockets on landing. In this situation the simulation assumes the seperatons should be fired as soon as the ion engine becomes available, and so the ion stage is assumed to have a high TWR, which results in mechjeb mis-timing maneuver nodes.
Merge branch 'dev' of https://github.com/MuMech/MechJeb2 into dev
1) Improved the landing predictions by better simulating parachute openings, using the predicted ASL of the landing site, better modeling the drag of parachute parts in various deployment states, deploying parachutes at a height above the landing site, rather than actual AGL, to prevent early opening when landing near mountains.
2) Added a new landing step "parachute control" that adjusts the height at which parachutes are semi deployed to control the overshoot / undershoot.
3) Added the ability to run additional simulations with added errors in the parachute deployment heights to create a good dataset from which to calculate 2) above.
4) Adjusted the location of "KSC" to be on the pad for 0.22
Merge pull request #228 from codepoetpbowden/dev

Parachutes precision and Changed the fuelflow simulation to not stage if the new stage does not detach any parts