is_lminion should only match lawful minions

is_lminion should only match lawful minions
When Angels were introduced, they were always lawful.  Somewhere along the
line, non-lawful angels were added, but is_lminion and uses of it was never
updated to address this change.  Among other things, this resulted in
non-lawful angels delivering messages via #chat that are only appropriate
for lawful angels.  That is addressed simply by changing the definition of
is_lminion, which must take a struct monst, not a permonst, to return valid
results.  Also, non-lawful angels should summon appropriate monsters, not
lawful minions.