Optional CFG variable to present users from overriding actuator intermediary positions

[sumghai]

As an extension of #39, I'd like to also suggest the following:

preventPresetOverride = true

Ziw noted that this seems like a rather restrictive flag, but the reason I'd like to see this is because I'd like to design a IR-powered payload rack carousel that "steps" to each angular position, and I don't want people to misconfigure my specific part in the VAB/SPH (otherwise, we'd have a situation where someone mucks around with my presets and ends up having the carousel turn halfway, making it impossible to grab something out of the rack).