new build which factory algo
- don't build land shells on water turtles or water shells on land turtles
- new factory placement algo:
	- taskqueues just passes "factory" to taskqueuebehaviour
	- which triggers finding a build site for every factory that the builder can build and we have none of
	- each site yields a score of ((300 * #spots in network) - (distance from builder times slowness multiplier)) * mobility type effeciency multiplier
	- ignore distance for aircraft cons
	- build the highest score
- add distance check to build site finder for amphibious cons moving from land to water or water to land, building non-mexes, so they don't waste lots of time moving from one to the other, excepting mexes and factories
- increase attack targetting ignore terrain long range threshold to 1000 from 650 (battleships, not destroyers)
- add fallback to turtle shell attachment: use the nearest turtle within three times the radius if there's none within half radius
- disable nonfunctional UnitDamaged danger registry in targethandler (all it's doing is erroneously registering dangers from itself)
- fix underwater mexes not registering construction begun
- fix bootbehaviour bug