Added note about migration guide

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@24217 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

wxPython/CHANGES.txt

@@ -2,35 +2,20 @@ CHANGES.txt for wxPython
 
 ----------------------------------------------------------------------
 
-2.5.0.x
+2.5.1.x
 -------
 
+(See also the MigrationGuide.txt file for details about some of the
+big changes that have happened in this release and how you should
+adapt your code.)
+
 Many, many little fixes, changes and additions done as part of the move
 to wxWindows 2.5 that I have forgotten about.
 
-Changed the import-startup-bootstrap process employed by wxPython such
-that wxWindows and the underlying gui toolkit are not initialized
-until the wxApp object is created (but before wxApp.OnInit is called.)
-This was required because of changes made to the C++ wxApp class.
-There are both benefits and potential problems with this change.  The
-benefits are that you can import wxPython without requiring access to
-a GUI (for checking version numbers, etc.) and that in a
-multi-threaded environment the thread that creates the app object will
-now be the GUI thread instead of the one that imports wxPython.  Some
-potential problems are that the C++ side of the "stock-objects"
-(wxBLUE_PEN, wxTheColourDatabase, etc.) are not initialized until the
-wxApp object is created, so you should not use them until then.  Also,
-you will probably not be able to do any kind of GUI operation unless
-you have an app object first, (even on Windows where most anything was
-possible beofre.)
-
 Added wxMirrorDC.
 
 Added wxIconLocation
 
-wxPython's setup.py script now expects to use existing libraries for
-the contribs (gizmos, stc, xrc, etc.) rather than building local
-copies of them.
 
 Added Python wrappers for the new wxVScrolledWindow, wxVListBox, and
 wxHtmlListBox classes.