title: Pickling an enum exposed by Boost.Python
body: <p>Is it possible to pickle (using cPickle) an enum that has been exposed with Boost.Python? I have successfully pickled other objects using the first method described <a href="http://www.boost.org/doc/libs/1_43_0/libs/python/doc/v2/pickle.html" rel="noreferrer">here</a>, but none of that seems to apply for an enum type, and the objects don't seem to be pickleable by default.</p>