fix issue #1046 - unseen monster reading scroll

Reported by copperwater "on behalf of Maud":  when hero hears an
unseen monster read a not-yet-discovered scroll of create monster
and doesn't see any new monster appear, the player is given a chance
to call the scroll something.  When hearing an unseen monster read
a not-yet-discovered scroll of teleportation, the label is revealed
but no such 'call it' opportunity is offered, so the player could
deduce which of the two scroll types it was for either case.

Provide an opportunity to supply a 'called' name for scrolls of
teleportation when heard being read, same as with create monster.
Surprisingly complicated to achieve.

Eliminated a couple of goto's in the process.

Fixes #1046

doc/fixes3-7-0.txt

@@ -1199,6 +1199,10 @@ applying a cream pie (always) or lump of royal jelly (sometimes) would use up
 	the object and then access its memory after that had been freed
 keep track of hero's pending movement points across save and restore
 give feedback if hero sees a monster become hidden under an object or water
+hero might hear unseen monster read scroll of create monster or scroll of
+	teleportation; when it was create monster, player was given a chance
+	to call it something but not when it was teleportation, allowing the
+	player to deduce which type of scroll it actually was
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository