github issue #481 - highlighting for #overview

Report states that the dungeon overview menu doesn't honor the
'menu_headings' option.  However, dungeon overview is not a menu.

Despite that, switch its hardcoded use of bold and inverse to use
the option value instead.  It doesn't really need two different
highlights and this allows user to control which video attribute
gets used.  If someone wants different highlighting for overview
than for menus, they're out of luck.

Fixes #481

doc/fixes37.0

@@ -436,6 +436,8 @@ attempt to make corpse or statue of a named player character would yield that
 homemade tin of very low nutrition corpse gave more nutrition than the corpse
 magic mapping performed while engulfed or underwater would display whole map
 	but then not switch back to the engulfed or underwater restricted view
+#overview used hardcoded bold and inverse for highlighting; switch to the
+	'menu_headings' option value so player has some control
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository

src/dungeon.c

@@ -3257,7 +3257,7 @@ print_mapseen(winid win, mapseen *mptr,
             Sprintf(buf, "%s: levels %d to %d",
                     g.dungeons[dnum].dname, depthstart,
                     depthstart + g.dungeons[dnum].dunlev_ureached - 1);
-        putstr(win, !final ? ATR_INVERSE : 0, buf);
+        putstr(win, !final ? iflags.menu_headings : 0, buf);
     }
 
     /* calculate level number */
@@ -3282,7 +3282,7 @@ print_mapseen(winid win, mapseen *mptr,
                 (!final || (final == 1 && how == ASCENDED)) ? "are"
                   : (final == 1 && how == ESCAPED) ? "left from"
                     : "were");
-    putstr(win, !final ? ATR_BOLD : 0, buf);
+    putstr(win, !final ? iflags.menu_headings : 0, buf);
 
     if (mptr->flags.forgot)
         return;