The recently added sanity check for monster maximum HP was giving
false complaints when Nd8 monster had N mhpmax. Most noticeable
for level 1 monsters (level 0 monsters use 1d4 instead of 0d8 and
weren't affected) but possible for higher level ones if they were
unlucky--from their own perspective--with all their d8 rolls.
Give level N monsters a minimum of N+1 HP, so minimum of 2 for
level 1 monsters, making 1/8 of those stronger. Same minimum for
level 0 monsters, 25% of which will become stronger now. (The pull
request's patch gave every Nd8 monster 1 extra HP; this only does
so for Nd8 and 1d4 ones which have rolled lowest possible amount.)
Also relax the sanity check so that existing to-be-3.7 save files
don't continue to trigger sanity complaints for existing monsters
that have the old minimum.
Fixes 365
abe4db6e60