Fix login issues

[clehner]

When I run a bb command with a fresh session, I get no output. When I run the command again, I get the proper command output. This may be an issue with handling the login cookies and responses.

[AstralSorceress]

I get the same issue if I have an empty .bbsession file. When a request is made in this state, blackboard redirects the user via javascript, which bb doesn't catch.