castle defense

[Furious Mental]

Since fortifications can sustain a number of militia units for nothing it shouldn't be too difficult to have enough troops to keep the fortifications firing. It also means not having to worry so much about a city with a one unit garrison being taken by FREAKIN BANDITS!!!

I noticed in some screenshots of building types that there are "improved towers" and "castle_cannon" (obviously not a final name). If the cannon are indeed cannon, hopefully they will know not to fire at one's own walls.