model_test.go

Structure flow around requests themselves and composition rather than
handlers and wrappers, the results are likely more readable (and
shorter).

Move all the user auth management business logic to a smart RawUser
object, to separate it from details of API handling. The result should
be more understandable: all critical changes are contained within a
single type.

Also, with all the workflow driven by Requests, we can get rid of the
boilerplate in the HTTP API server and replace it with a tiny tiny
layer of reflection.