Move some hard-coded string arrays into data files.

Random epitaphs, engravings and hallucinatory monsters now
live in text data files.

src/pickup.c

@@ -2040,7 +2040,7 @@ struct obj *box;
 	    (void) add_to_container(box, deadcat);
 	}
 	pline_The("%s inside the box is dead!",
-	    Hallucination ? rndmonnam() : "housecat");
+	    Hallucination ? rndmonnam(NULL) : "housecat");
     }
     box->owt = weight(box);
     return;