add missing slots 'tp_del' (Py>=2.3) and 'tp_version_tag' (Py>=2.6)
add missing slots 'tp_del' (Py>=2.3) and 'tp_version_tag' (Py>=2.6)

bhy/cython-haoyu,bhy/cython-haoyu,bhy/cython-haoyu,bhy/cython-haoyu