For v1.1.0rfc5, patch series version 1

I tentatively plan to merge this October 4th at 3PM EST, declaring version 1.1.0 immediately after, unless there is some unresolved discussion or another patch series to include.

Now, on this patch series, from the last commit message:
This updated RFC version completes other-namespace extensibility for DFXML elements, corrects some logical representation errors, and adds flexibility for extension element locations.