fixed an old wheel-event bug and added version number to history, please propagate

collects/2htdp/universe.rkt

@@ -234,7 +234,10 @@
     "numlock"
     "scroll"
     "wheel-up"
-    "wheel-down"))
+    "wheel-down"
+    "wheel-left"
+    "wheel-right"
+    ))
 
 (define-syntax (big-bang stx)
   (define world0 "expects an expression for the initial world and at least one clause")

collects/teachpack/2htdp/scribblings/universe.scrbl

@@ -358,6 +358,8 @@ Second, some keys have multiple-character string representations. Strings
 @item{@racket["scroll"]}
 @item{@racket["wheel-up"]}
 @item{@racket["wheel-down"]}
+@item{@racket["wheel-left"]}
+@item{@racket["wheel-right"]}
 ]
 
 @defproc[(key-event? [x any]) boolean?]{

doc/release-notes/teachpack/HISTORY.txt

@@ -1,10 +1,12 @@
 ------------------------------------------------------------------------
+Version 5.2.1				  [Thu Jan 19 11:36:19 EST 2012]
 
 * added: universe.rkt now comes with a game-pad simulation option 
-  A game-pad is a special-purpose key handler plus an icon that maps out
-  the legal key strokes. 
+  A game-pad is a special-purpose key handler plus an icon that 
+  maps out the legal key strokes. 
 
 * fixed
+  -- wheel-left and wheel-right events work properly as key events now
   -- on-receive doesn't have to exist for universe/world interactions 
   -- name clause accepts strings and symbols 
   -- doc typos