Manageable and Secure Service Model

Attached is a proposed replacement for the current proposed replacement for
the management model. While I co-authored the existing model with the
meta-relationship, it proved confusing in recent reviews. Hence the
re-proposal. 

I'd like to discuss both models at the F2F. If we can get agreement on
Section 2, I'll produce section 3 shortly there after.

Thanks,
Zulah