Update release script to run under Python 3
Bumped to 0.8 in preparation for next release.
Updated changelog
Backed out changeset: 7292c3a723e3
See https://bitbucket.org/pypa/setuptools/commits/7292c3a723e3b7b6fdd2bede2374dd1777809e7d for discussion
Added tag 0.7.3 for changeset d212e48e0cef
Bumped to 0.7.4 in preparation for next release.
Update version to indicate a range of versions when discussing upgrade from Distribute
Merge 0.7.3 release
Added tag 0.8b1 for changeset 74c6c1226805