add zmq.utils.sixcerpt
add zmq.utils.sixcerpt

excerpts of six.py. Currently, only `reraise`
swn1/pyzmq,swn1/pyzmq,swn1/pyzmq,Mustard-Systems-Ltd/pyzmq,ArvinPan/pyzmq,caidongyun/pyzmq,ArvinPan/pyzmq,Mustard-Systems-Ltd/pyzmq,dash-dash/pyzmq,yyt030/pyzmq,caidongyun/pyzmq,yyt030/pyzmq,Mustard-Systems-Ltd/pyzmq,ArvinPan/pyzmq,caidongyun/pyzmq,yyt030/pyzmq,dash-dash/pyzmq,dash-dash/pyzmq