The goal of this rework is to make it so I can pass around platform.User
instead of a pair of models.Organization and models.User. This is useful
for reason I kind of forget now, but it started with working on
notifications and ballooned massively from there into refactoring a
number of things that were bugging me.
This also includes a tiny amount of work on server-side events (SSE).
* background stuff lives inside the platform now, which I need for
having it push updates through SSE
* userfile now lives in the platform, under file, so other platform
functions can safely use it
* oauth is broken into pieces and inside platform because other stuff
was calling it already, but badly.
* notifications go into the platform as well
I'm settling on the idea that strings should never be returned from the
userfile system. Instead, indicate which collection you want and pass
objects across.
