allow for migration files to be fixture files or schema files, and manage fixtures in lock step with schema changes

I have come across the need for loading fixtures as well as database schema in a particular order. And I would also like the ability to not load fixtures if not needed (like a production database migration). This changeset will allow one to specify on the command line if they would like to have fixtures applied in the migration or not.

(please note there are several instances where I needed to change the import to my fork to make the build work, obviously all those instances should be removed from the merge.)