fix migration of author_name and author_username
simplify some of the logic and get some tests in place to cover them. TDB: test against actual site to ensure the changes to the logic don't break a real environment, but still work with the tests..
move creation of test user to test setup, rather than just in the new test_migrate_comment_with_creator() method
use member.getProperty('fullname') if member.fullname is an empty string. Not sure in what case this would happen, but it did happen in my site migration
Merge pull request #23 from bdbaddog/fix_comment_user_migration

fix migration of author_name and author_username