Hack wxMSW wxNotebook to show the text controls correctly initially.

Add an Update() call to ensure that text controls in the initially selected
notebook page are shown correctly. It's almost certainly not the right fix for
the real bug that results in text controls not being shown when the notebook
comes up but it doesn't cost much and at least allows us to get correct
appearance for the themed notebooks.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@69793 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/notebook.h

@@ -194,6 +194,9 @@ protected:
 
   // true if we have already subclassed our updown control
   bool m_hasSubclassedUpdown;
+
+  // true if we already refreshed the current page after showing the window
+  bool m_doneUpdateHack;
 #endif // __WXWINCE__
 
 #if wxUSE_UXTHEME