Guidebook update: armor and other objects

Guidebook update:  armor and other objects

Condense the clunky one entry per line table of suits of armor and
their AC values in Guidebook.mn.  Guidebook.tex uses a two-column table
that I've left alone.

Mention all the other types of armor instead of leaving out gloves and
shirts.  For armor commands, mention that P and R work.

Rings:  describe their interaction with gloves.  For ring commands,
include a pointer to amulets.

Amulets:  for amulet commands, mention that A, W, and T work.

Tools:  mention that some can be worn and include a pointer to amulets
for the relevant commands.  Also, that some can be wielded as weapons.

Boulders and statues:  boulders can be pushed and smashed, statues can
be smashed.

Gold:  not subject to blessing or cursing.  goldX option affects BUCX
filtering.