OGL fixes; documentation fixes; dialog editor updates

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@447 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/dialog.cpp

@@ -490,6 +490,7 @@ void wxDialog::Centre(int direction)
 // Replacement for Show(TRUE) for modal dialogs - returns return code
 int wxDialog::ShowModal(void)
 {
+    m_windowStyle |= wxDIALOG_MODAL;
 	Show(TRUE);
 	return GetReturnCode();
 }