Add whatis_moveskip option to change fast-moving cursor

Previously the "fast-moving" when getting a target location
was always by 8 units. If this option is on, fast-moving
will instead skip the same map glyphs. This should be much more
useful for blind players.

src/options.c

@@ -233,6 +233,7 @@ static struct Bool_Opt {
     { "vt_tiledata", (boolean *) 0, FALSE, SET_IN_FILE },
 #endif
     { "whatis_menu", &iflags.getloc_usemenu, FALSE, SET_IN_GAME },
+    { "whatis_moveskip", &iflags.getloc_moveskip, FALSE, SET_IN_GAME },
     { "wizweight", &iflags.wizweight, FALSE, SET_IN_WIZGAME },
     { "wraptext", &iflags.wc2_wraptext, FALSE, SET_IN_GAME },
 #ifdef ZEROCOMP