This small change will allow to extend south.management.commands.schemamigration.Command and override MIGRATION_TEMPLATE.
Rationale behind the change:
We use one code base but different migration sets for different deployments because database schema is dependent on a couple of settings which enables/disables some functionality. I want to be able to create my initial migrations quickly. I also need to put some tweaks for every initial migration. In my case it was adding "depends_on" attribute. Doing it manually every time is a pain. This change allows to override MIGRATION_TEMPLATE and thus easily add tweaks I need.