renamed wxMotif::wxTLW::DoCreate() to XmDoCreateTLW() to avoid conflicts with

renamed wxMotif::wxTLW::DoCreate() to XmDoCreateTLW() to avoid conflicts with
DoCreate()s in derived classes and removed DoDestroy() entirely because there
was really no advantage in having it (it can't be called fom base class dtor)

also made XmDoCreateTLW() pure virtual which required changing
IMPLEMENT_DYNAMIC_CLASS into IMPLEMENT_ABSTRACT_CLASS for wxTopLevelWindow in
common code but this made sense anyhow because wxTLW should be an ABC anyhow

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@35508 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775