fix #K3472 - stale perm_invent when engraving

Engraving with a weapon which has known enchantment or with a magic
marker which has known charge count that decremented the amount did
so without updating the persistent inventory display.  Report was
for curses but applied to every interface that can show perm_invent.

This includes some reformatting (mostly
 if {
 }
 else {
 }
to
 if {
 } else {
 }
multiple times; also add some new braces after 'if' or 'else' where
one half already had those and the other didn't).  And removal of
some unnecessary 'register' designators.

Plus fix up one sanity check which complained if number of charges
being used was more than a marker had, but then let the engraving
continue and decrement the count by that large amount.  If that
impossible situation ever occurred, it would result in a marker
with negative charges.

doc/fixes37.0

@@ -556,6 +556,8 @@ shopkeepers can remove pits and webs
 perm_invent: when buying shop goods using itemized purchasing while persistent
 	inventory window was enabled, the prices of unpaid items went away as
 	soon as any item was bought (actual item-by-item purchase worked ok)
+perm_invent: making an engraving which reduced known enchantment of a weapon
+	or known charge count of a marker didn't update persistent inventory
 change getloc fastmove keys in number_pad mode from hardcoded HJKL to the
 	run/rush movement keys (meta+number)
 allow using rush/run prefix key in getloc to fastmove the cursor