Start to make updating local packages possible
Return of db backend
Rename local_versions to local_releases
Create values package for Path and Version
Rename values.Version to values.ReleaseValue
Add 1st version of Package, Release, File models

These models will very likely later prove to require additional pypi metadta
Better initializedb
Change download_package url segments. Update links in templates.
Add test settings, ignore test.sqlite
py.test fixtures for managing db sessions
Convert views to use DB lookups
Add File.kind field
Stop creating md5s on the file system
Remove debug_toolbar from development settings
Move fixtures to conftest.py
Release.version and Release.package_id should be unique together
Drop database tables post-test run
Add Package.by_name method
Rename TestView to TestDownloadPackage
Remove reliance on self.package from Release.__repr__