Changed (selected) mission item color to primaryButton instead of buttonHighlight
Adjusted some colors for better contrast
Removed a few JavaScript exceptions caused by the order of object destruction

Instead of hardcoded "QGroundContorl" strings

This makes VehicleComponents reusable from core plugin without
requiring override of prerequisiteSetup

- Fix imports to support 5.7
- Move properties to correct location

* Add volt/amp calculators

* Correct amps per volt calculation