moved weakref_types to a test; fixed import for source distribution


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/pathos/dill@536 8bfda07e-5b16-0410-ab1d-fd04ec2748df
tag for dill-0.2a release


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/pathos/dill@537 8bfda07e-5b16-0410-ab1d-fd04ec2748df
tag release for dill-0.2a1


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/pathos/dill@538 8bfda07e-5b16-0410-ab1d-fd04ec2748df
Merge branch 'master' of https://github.com/uqfoundation/dill