Extended ProcessTextCommand so processes SETFOCUS/KILLFOCUS; checked for valid

HWND in wxBuddyTextWndProc so if the event handler kills the HWND, it doesn't crash;
added support for disabling 3D effect in buddy window.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@9070 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/spinctrl.h

@@ -94,6 +94,9 @@ protected:
     // the handler for wxSpinButton events
     void OnSpinChange(wxSpinEvent& event);
 
+    // Handle processing of special keys
+    void OnChar(wxKeyEvent& event);
+
     // the data for the "buddy" text ctrl
     WXHWND     m_hwndBuddy;
     WXFARPROC  m_wndProcBuddy;