Make the pre - generated wreck algorithm a bit smarter

[JohnBWatson]

I always notice some rather strange combinations of wrecks pre - generated by the game, to the point where they would likely break immersion. It'd be fairly simple to make them a bit less bizarre with a few alterations:

1. Battle wrecks should be between two factions with stations currently in the system. (avoid bizarre implications of battles between allies and skirmishes with no apparent faction or unreasonably distant/allied participants)

2. Battle remains should try to get reasonably equal point - distributions between the two sides. (avoid common appearance of one - sided battles between 3 corsair Is and a midgame - tier gunship)

3. Wrecks of ships from battles between factions should have at least a chance to spawn some of their default equipment, possibly with a higher damage chance due to the possibility of the wrecks already having been passed over by looters. (loot chance can be reduced significantly for balance)

4. Individual wrecks should contain items appropriate for the current system level. If they're intended as trader wrecks with no special qualities, they can keep default equipment. If they're intended as mercenary or pilgrim wrecks, they should have stuff that give them a chance to survive a fight against the locals. (Avoid spawning barely - armed civilian freighters deep in the UT.