Restrict the teleportation notification to actual teleportations

teleds() is used for more than just teleportations, the teleportation message
was also given when mounting a steed.

Trying out a new bit flags method parameter design pattern.

include/hack.h

@@ -490,6 +490,11 @@ enum bodypart_types {
 #define MENU_FULL 2
 #define MENU_PARTIAL 3
 
+/* flags to control teleds() */
+#define TELEDS_NO_FLAGS   0
+#define TELEDS_ALLOW_DRAG 1
+#define TELEDS_TELEPORT   2
+
 /*
  * Option flags
  * Each higher number includes the characteristics of the numbers