U856 - cockatrice and nurses

U856 - cockatrice and nurses
One from the way-back machine.  A nurse would hit you-as-cockatrice repeatedly
and never turned to stone.  With this change, nurses will turn to stone (and
also don't heal cockatrices, which seems fair).  I considered giving them
gloves, but that seemed like too much effort.  There are other cases where a
monster "hits" but will not petrify.  However, it doesn't seem like passiveum
detects all the specific ways the monster "hit" you so I left them alone.