Reported by vultur-cadens: slow digestion from wearing white dragon
scales/mail blocked per-turn hunger and didn't cause any hunger,
unlike ring of slow digestion which blocks per-turn hunger but still
causes some hunger as a worn ring itself. If no rings or amulet
were worn, wearing the suit prevented the hero from ever burning any
nutrition.
Change to treat wearing the suit to be quite a bit like wearing a
ring, unless hero is also wearing an actual ring of slow digestion
(then the hunger cost of the suit is 'free').
Wearing a ring of slow digestion and another ring consumes two units
of nutrition every 20 turns, no matter what suit. Wearing white
dragon scales/mail and two non-slow digestion rings now consumes three
units of nutrition every 20 turns. Using the suit to effectively get
an extra ring finger isn't free.
Fixes#742
e8374b36a1