Improve feedback loop

[bvanderveen]

Current feedback:

• Build
• Kill old process
• Optionally reset X-Plane (home runway, at-altitude, other scenario)
• Unlock the brake if on runway, extend flaps, deal with gear
• Start new process

Meanwhile X-Plane chews my CPU.

Need to get it down to one command to unpause X-Plane process, launch control process, reset scenario, etc.

[bvanderveen]

See also #13.