This change organizes the message docs by topic rather than letting
autodoc organize methods by the order they appear in the _proxy.py file.
These were not previously included so they're technically all brand new.
There are some minor adjustments made to the docstrings as they weren't
known to be raising warnings before due to not actually being included
anywhere.
Change-Id: Id4b8f08015a6f00b8134fcd2a01506562d9787fb
6f59061ec4