With public local sites, it's possible that the 'user' link in the session

resource will be broken. This is because the users resource only includes users

who are part of the given local site.
This change makes 'rbt status' work a little better in this case. We don't

actually need any data from the user resource, since all we're looking up here

is the username. In this case, we can just use the title attribute of the link,

which also happens to save us an API request.

Verified that 'rbt status' still works.
Ran unit tests.