Fixed reference vectors not updating properly when building a ship with symmetry mode on.

* Gyroscope override no longer disables attitude hold,
* Only one control panel group can set thruster tags at a time.

* Fixed thrust limits being applied unilaterally instead of selectively,
* Added group-based tagging.

Active control and calibration are now disabled when RC autopilot is on -- this allows the latter to be at least semi-functional.

Reduced flickering.

* Improved active throttling -- now interpolates between full and calibrated minimum instead of between full and zero,
* Additional multi-core support -- thruster assigment and calibration now run on a background thread.

Full support of triangular thruster arrangements

Aditional improvements for hover and landing mode accuracy.

* Nerfed gyroscope compensation (to discourage gyro spam),
* Removed relaxed thrust limits in [THR] and [THR][STAT] modes
(not neccessary anymore, as this is what [RCS] mode is for).

Partial multi-core support.