Changes domove() code to allow displacing peaceful monsters.
Specifically, is_safepet() now returns true if the monster is peaceful.
Peacefuls are slightly pickier than pets about whether they consent to
being displaced: they will not displace if a goodpos() check fails for
the displaced space, or if there is a trap on the displaced space, or if
they are your quest leader. is_safepet should probably be renamed to
something else.
In the process of doing this, some other changes were made: the code now
checks whether the player and monster should be swapping places at all
first (previously it ran some code for displacing pets out of traps
first, which was a little weird if the displacement didn't actually
happen.)
In the original commit for this, I needed to guard the spoteffects()
call made in domove with a clause testing whether the player actually
moved; it was previously possible to fail to displace a monster and then
re-trigger a trap on the space you were still standing on. However, the
devteam has apparently put in an if (u.umoved) clause in the same place
and serving the same purpose.
2ee09b9210