Set neutral attitude (anger = 0) to IGNORE.

Right now creatures with 0 anger will be ordered to track down the
player. It seems more realistic to have 0 anger creatures ignore the
player (as they aren't hostile). The end result of this is wildlife are
slightly less likely to attack if the player gives them a wide berth,
compared to before where they were guaranteed to attack eventually.
Cougar stalk change

Changed MTRIG_TIME to MTRIG_STALK; now it only rolls to increase after a
creature starts to follow the player instead of as soon as they see
them. Name change was in-case someone wanted to implement an actual
MTRIG_TIME later for something else.
Merge remote-tracking branch 'origin/Balance'