Add downgrade support to migrate.  This is really necessary for doing real migration development.  Modified all existing migrations to support it.

Signed-off-by: Steve Howard <showard@google.com>



git-svn-id: http://test.kernel.org/svn/autotest/trunk@1336 592f7852-d20e-0410-864c-8624ca9c26a4
6 files changed