Fix: thruster certification and races
Gate courses now show which gate is next.
- Fixed course checkpoints spawning outside starter scanner range.
- Fixed the objective marker tracking another mission during a course.
- Changed checkpoints to be named Gate 1 through Gate N.
- Added a cleared mark on each gate as you cross it.
- Added a course readout with the next gate and the lap clock.
- Added a chime when a gate registers.
- Added a notice when the lap clock runs out.
- Changed the lap clock to start at Gate 1.
- Reduced the length of every gate course.
- Changed race times to be measured from Gate 1 to the finish.