Apply paxed's DEBUG patch to remove DEBUG/D_DEBUG.

Move debugging output into couple preprocessor defines, which
    are no-op without DEBUG.  To show debugging output from a
    certain source files, use sysconf:

    DEBUGFILES=dungeon.c questpgr.c

    Also fix couple debug lines which did not compile.

This also includes fixes due to Derek Ray to depugpline to work better
on other platforms.

src/pickup.c

@@ -903,9 +903,7 @@ int how;			/* type of query */
 		(*pick_list)->item.a_int = curr->oclass;
 		return 1;
 	    } else {
-#ifdef DEBUG
-		impossible("query_category: no single object match");
-#endif
+		debugpline("query_category: no single object match");
 	    }
 	    return 0;
 	}