complete domain independence

[Chris Muller]

I'm happy to report I have improved Magma so that the
MagmaCollectionIndex is no longer required in the server image.

This was a very annoying "exception" to the feature that the server
does not need any domain classes.  Custom index types are rightfully
considered part of the domain, and requiring them (unnecessarily, it
turned out) in the server means a completely static codebase in the
server was not possible.

Now, with r40, it will be.

Oh, also, r40 will automatically upgrade legacy repositories.  You'll
see a warning once, a brief upgrade will occur and you're ready to
roll with the r40 code.  Further, it is planned that all future
releases will be able to co-exist with r40.

Just a few more things to do, r40 will be a worthwhile upgrade..
thanks for your patience.

 - Chris