rfctr: use relative imports in oxml.__init__
rfctr: use relative imports in oxml.__init__

python-openxml/python-docx,SimplyAgree/python-docx,jean/python-docx,holli-holzer/python-docx,yurac/python-docx,tanyunshi/python-docx,Nuos/python-docx,eruffaldi/python-docx