A massive rewrite affecting both the pickle and cPickle module documentation.  This addresses previously undocumented parts of the public interfaces, the differences between pickle and cPickle, security concerns, and on and on.
A massive rewrite affecting both the pickle and cPickle module
documentation.  This addresses previously undocumented parts of the
public interfaces, the differences between pickle and cPickle,
security concerns, and on and on.

Fred please proofread!

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator