Menus in the curses interface would honor a digit as a selector
character ("letter" :-) for PICK_ANY menus but forced it to start a
count in PICK_ONE menus. This fixes that, although the menu where I
was using digits as selectors (not included) has been changed to use
letters so this fix isn't being exercised anymore.
Also, add a couple of comments about persistent inventory.
f25b5c4627