Windows installer: update dialogs, program groups, etc, to 2.1 alpha 1.

PCbuild/python20.wse

 Document Type: WSE
 item: Global
   Version=5.0
-  Title=Python 2.0
+  Title=Python 2.1 alpha 1
   Flags=00010100
   Languages=65 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
   Japanese Font Name=MS Gothic
@@ -64,19 +64,19 @@ item: End Block
 end
 item: Set Variable
   Variable=APPTITLE
-  Value=Python 2.0
+  Value=Python 2.1 alpha 1
 end
 item: Set Variable
   Variable=GROUP
-  Value=Python 2.0
+  Value=Python 2.1
 end
 item: Set Variable
   Variable=PY_VERSION
-  Value=2.0
+  Value=2.1a1
 end
 item: Set Variable
   Variable=MAINDIR
-  Value=Python20
+  Value=Python21
 end
 item: Get Registry Key Value
   Variable=PROGRAM_FILES