Skeleton tweak (No war-weariness)

[Tasunke Witka]

While I am content with Tigers, Pyre Zombies, and Diseased Corpses using war weariness, (although I have my eye on Diseased Corpses :p) I think that the Skeleton unit (and Skeleton summon) should not cause War Weariness.

For one, as removing maintenance costs is more difficult to code, I think that this could be a fitting replacement. For two, it allows for skeletons to be more readily used on the offensive (making the Sheaim less likely to be the 'bad guys' among other things). Currently the only successful use of skeletons to date has been on the DEFENSIVE.

It also makes the Tower of Necromancy slightly more relevant.