Fix dumb default staging decisions

[herbal space program]

So I've been playing career mode in 0.90 with "hard" settings (actually I retained f5 capability for use only in case of bugs), and the loss of the ability to revert has highlighted some silly features of the VAB editor for me. One particularly glaring instance of this is the fact that when you add a chute to a vehicle, instead of going in its own stage at the top, which is pretty much always where you'd want it, it always goes together with what ever engine activation stage is on top. Nobody ever wants to pop a parachute at the exact same moment they activate an engine! The chute should always default to its own stage at the end of the sequence, and this does not seem too hard to implement. In a similar vein, launch stabilizers seem to get strewn about the staging sequence randomly when you place them, which is extra dumb because of course you always want them at the bottom. In general, whatever algorithm the game uses to decide where in the staging sequence to put parts when you place them makes no sense to me at all. It should definitely be made more logical.