Addd migration for rating sums.
Merge
Added new site to README.
Bump Mezzanine version to 1.4.2
Version bump to 0.8.1
Added tag 0.8.1 for changeset e57e03eda269
Update automated changelog, model graphs.
Use set_default_images in product_db command.
Added Sam Kingston to AUTHORS
Merge branch 'master' of ssh://github.com/stephenmcd/cartridge