Do not represent default "internal" DQMH request in the relationship diagrams

From Darren Nattinger:

Every DQMH module sends a request to itself by virtue of Stop Module.vi or Get Module Execution Status.vi, which are framework-level implementations. I wonder if you should ignore those two requests and only draw the little loop request arrow on top of a module box if it calls any of its own requests other than those two? I think that would be more helpful on those Antidoc diagrams. As it stands, every DQMH module box has the little self-loop arrow, which doesn't really give us any useful information. A module sending a request to itself is not terribly common outside of private events, and as such, I feel like it would be helpful for understanding module communication (and possibly debugging) if those arrows were only drawn when their info might be useful.

NOTE: update the Preamble section to explain that.