Add support for RangeMultiplier, RangeModelType and MultipleAntennaMultiplier

[tivec]

I frequently use this planner, but have found myself using the root method of calculating distance, as well as multiple antenna multipliers.

Would it be possible to implement support for this? The math is fairly uncomplicated, and it'd make for an even better planner :)

Obviously, all three values would be needed as options, since they're used to scale and balance out the mod parameters.

[ryohpops]

Implement RangeMultiplier and MultipleAntennaMultiplier with a57dcb3

[ryohpops]

Support for RangeModelType is relatively hard. I will consider it on coming reconstruction of this project.

[4o66]

Until Range model results are displayed, could we get the option to select it on settings to reflect that?

[ryohpops]

Oops, it seems I forgot to make that prototype hidden.
Currently the selector makes no change of calculation or display.