autounlock overhaul

This gives the player more control over what autounlock does.  It is
now a compound option rather than a boolean, and takes values of
  autounlock:none
  !autounlock or noautounlock (shortcuts for none)
  autounlock:untrap + apply-key + kick + force (spaces are optional
    or can be used instead of plus-signs, but can't mix "foo bar+quux")
  autounlock (without a value, shortcut for autounlock:apply-key).
Default is autounlock:apply-key.

Untrap isn't implemented (feel free to jump in) so is suppressed from
the 'O' command's new sub-menu for autounlock.  It's parsed and
accepted from .nethackrc but won't accomplish anything.

[Just musing: it should be feasible to kick in direction '.' to break
open a container or #force to an adjacent spot to break open a door.
If that was done, autounlock:kick+force (or more likely autounlock:
apply-key+kick+force when lacking a key) would resort to force if hero
couldn't kick due to wounded legs or riding.

This changes struct flags so increments EDITLEVEL again.

This includes pull requests #750 from entrez and #751 from FIQ but was
entered from scratch rather than using use their commits.

Closes #750
Closes #751

include/optlist.h

@@ -124,8 +124,11 @@ opt_##a,
            set_in_game, No, Yes, No, NoAlias, "edit autopickup exceptions")
     NHOPTB(autoquiver, 0, opt_in, set_in_game, Off, Yes, No, No, NoAlias,
                 &flags.autoquiver)
-    NHOPTB(autounlock, 0, opt_out, set_in_game, On, Yes, No, No, NoAlias,
-                &flags.autounlock)
+    NHOPTC(autounlock,
+                (sizeof "none" + sizeof "untrap" + sizeof "apply-key"
+                 + sizeof "kick" + sizeof "force" + 20),
+                opt_out, set_in_game, Yes, Yes, No, Yes, NoAlias,
+                "action to take when encountering locked door or chest")
 #if defined(MICRO) && !defined(AMIGA)
     NHOPTB(BIOS, 0, opt_in, set_in_config, Off, Yes, No, No, NoAlias,
                 &iflags.BIOS)