Tweak to Unit Fortification

[xsgenefuzz]

I really wish that units would automatically enter "alert" after completing fortifications instead of going fully to sleep. There have been multiple times when I've been fighting a major battle on one front, and then I discover that way over on the other side of my empire, there's this one unit that's been banging on the walls of one of my settlements for several turns already. And my unit on the tile is just sitting there letting the fortifications be torn down. The warning system is supposed to prevent this from happening, I guess, but it doesn't seem to always work. In any case, I think that just having units go into "alert" mode after fortifying would be the best solution.