fix #K112 - fumbling vs autoopen

Report complained that having autoopen not work when fumbling was
inconvenient and mentioned that the "ouch! you bump into a door"
result didn't take any time.  This updates the documentation to
state that autoopen won't work while fumbling (so the inconvenient
behavior persists) but changes movement so that bumping into a door
now takes time.  (Despite "ouch!", it doesn't inflict any damage.)

Also, document the recently added autounlock option.

dat/opthelp

@@ -9,6 +9,8 @@ autoopen       walking into a door attempts to open it            [TRUE]
 autopickup     automatically pick up objects you move over        [TRUE]
 autoquiver     when firing with an empty quiver, select some      [FALSE]
                suitable inventory weapon to fill the quiver
+autounlock     when opening a locked door or looting a locked     [TRUE]
+               container while carrying a key, offer to use it
 BIOS           allow the use of IBM ROM BIOS calls                [FALSE]
 blind          your character is permanently blind                [FALSE]
 bones          allow loading bones files                          [TRUE]