fix B18002 and B18003 - #rub worn blindfold and wield_tool() feedback

Prevent #rub from wielding an item that is already being worn
(which should narrow things down to the various types of eyewear;
other tools and weapons that go through wield_tool() can't be worn).
Fix up the wield_tool message spacing in the process.

     This moves wield_tool() from apply.c to wield.c.  Some plural
handling for messages is included; it is feasible to try to #rub a
"pair of lenses" or a stack of N candles.

src/dig.c

@@ -1,4 +1,4 @@
-/*	SCCS Id: @(#)dig.c	3.4	2003/01/08	*/
+/*	SCCS Id: @(#)dig.c	3.4	2003/01/29	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -820,7 +820,7 @@ struct obj *obj;
 
 	/* Check tool */
 	if (obj != uwep) {
-	    if (!wield_tool(obj)) return(0);
+	    if (!wield_tool(obj, "swing")) return 0;
 	    else res = 1;
 	}
 	ispick = is_pick(obj);