Revision 812

(ClassGenDialog.__init__): Rearrange the
        order that the controls are created so that tabbing works correctly.
(ClassGenDialog.OnOK): Renamed from _OnGenerate() so that the
        wxDialog can handle the default button correctly.
(ClassGenDialog.OnCancel): Renamed from _OnCloseBtn() for the
        same reasons as for OnOK.
(GenUniformPanel._OnRetrieve): Call wxBeginBusyCursor/wxEndBusyCursor
        when we ask the table for the maximum/minimum values of a field
        which could take a very long time.