Migration script to add encoded version and release strings for packages

I snuck in a tweak to the docs I copied from the Fedora wiki that included a really lame sentence.

The existing migrations were under test/unit/server/migrations and not being run by our scripts. There wasn't really a need for the distinction so I moved them up to server and was able to remove the import except block that added .. to the source path in the process.

The actual meat of this is in the 0007 migration script and its associated test case.