Dogfight AI behavior tweaks

[JOBBIN9422]

Current set of changes to the dogfighting AI's behavior:

• attempt to shake pursuers by jinking, breaking, and optionally cutting the throttle
• Increase backSenseRange angle to 45 degrees to broaden the region behind the aircraft where enemies are considered to be strictly "behind"
• break and maneuver immediately upon taking damage
• break when a missile is launched
• add randomness to flare dispense intervals, other decision-making
• increase max. attempted gunfire range to 700m (from 500m)
• force attempt a climb when below minimum acceptable altitude

Please test this and decide if the AI changes are welcomed! I was using YS2015 as a baseline for comparison.

Some ideas of "test" scenarios:

• Dogfight auto-demo from main menu - how do the AI handle duels and large, dynamic fights? Do they avoid terrain, break convincingly, flare correctly, etc. ?
• Dogfight the AI with and without wingmen (on either team).
• Dogfight the AI with and without missiles enabled.

[NodokaHanamura]

I recently forgot to add @pasutisu to the org I resolved that, I've added him to the assignee list. No pressure, take this on at your leisure, boys. 😊