upstream bump
This is a rewrite of the old session system in Barista. The old one
tried to be a little cute with Persona and cookies, as well as having
separate login and logout pages/resources. Likely, complicated factors
around these are what caused the problems in #61 and #69. This rewrite
is simpler and better structured for debugging; it also sticks closer to
the intentions of Persona. Instead of having login and logout pages,
we've changed over to a "session manager" page that acts as a Persona proxy.
Added new method to Noctua and some bugfixes; this technically fixes #61
and fixes #69. Although more testing could be done, it seems better so far.