"Withdraw Army" bug

[Szilard]

Units which have been evaporated before a relevant "Withdraw Army" event occurs may still reconstitute and appear as reinforcements. Another persistent critter which has been there since TOAW 1.

Also: The existence of evaporated reconstiutable units slows the "checking replacements" phase *way* down; I think more so than in ACOW. Some kind of glitch might have crept into the beta patch, I guess, but this has always been a pain-in-the-butt slow phase and reworking the code to make it faster would be highly appreciated. Even if it meant eg changing the replacement priority for evaporated units versus on-board units in the algorithm, if that has anything do with it.