add detect.baditems; _proxy_helper doesn't barf on non-proxy;
add safe keyword for pickles, detect.badobject, detect.badtypes, detect.errors


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/pathos/dill@616 8bfda07e-5b16-0410-ab1d-fd04ec2748df
Merge branch 'master' of https://github.com/uqfoundation/dill