This fleshes out the docs for Active Directory, helping to make some

parts a lot more clear for future maintenance work. These docs cover the

details of function arguments and return types, as well as Django

settings and their siteconfig equivalents.
Some older code has also been cleaned up a bit, better conforming to

current coding styles and simplifying logic.
The backend also now has its own logger, which allows us to simplify

the various logging calls and make them more useful.

Unit tests pass.
Built the docs and checked through them for reference errors, typos, and

build errors.