[Toaster] RFC on change in migration support

[Brian Avery]

As Toaster releases continue, maintaining database migrations from the
dawn of time is getting increasingly difficult, time consuming for the
developers, and difficult to test.

I'd like to propose that we *only* support migrations of the database
from the previous release to the current one. If we had done that for
this release, for instance, the jethro toaster would be able to
migrate a fido database; but not an earlier one.

If the need to migrate earlier databases is needed you could run
earlier releases of toaster to keep migrating the database, release by
release.

I'm uncomfortable promising migrations that work since the beginning
of toaster, since I know we don't/can't test the large number of
combinations.  Furthermore, I'd prefer to see development time spent
more on the many issues & features of Toaster.

¿Comments/Thoughts?

-b