- Tidied up the code a little and grouped mixer types in model.js.
- Removed second motor from all fixed wing mixers that aren't differential thrust. A bug was discovered that if an FC only has a single motor output, and 2 motors are set in the mixer, the motors won't work.
- Added mixer for V-Tail with differential thrust
- Enhanced the new servo button. Clicking it now selects the next available servo number, rather than just 0.