fix issue #1025 - stuck in Mines' End

Issue reported by AndrioCelos:  if you arrived at the Wine Cellar
variation of Mines' End by falling or by level teleportion instead
of via the stairs, you could end up in the treasure chamber.  If
you lacked a way to dig or to level teleport, you would be stuck.
Since most of that level is undiggable, it would likely fill up with
monsters before one that could dig would appear close enough to dig
to you and you'd eventually starve.

The initial report suggested including an escape item in the treasure
chamber.  This adds a teleport region to control hero's arrival spot
instead.  There was a suggestion fix things this way from copperwater
but I didn't notice that until I had already chosen this method....

Fixes #1025

doc/fixes3-7-0.txt

@@ -1206,6 +1206,8 @@ hero might hear unseen monster read scroll of create monster or scroll of
 wizard mode wish for terrain while on a fountain|sink spot made the counter
 	for number of fountains|sinks become one too big; would affect level
 	sound messages if all fountains|sinks were eventually destroyed
+add a level arrival region to the Gnone King's Wine Cellar variation of the
+	Mines' End level so that hero can't end up in the treature chamber
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository