imap: offline mode for debugging/testing
Going through the remote authentication and syncs is too cumbersome for mail testing. This should implement a quick pass through the soledad and keymanager initialization routines so we're able to pass an --offline flag that only initializes the local instance of soledad.
I won't worry too much about displaying of states, since (a) This is not a user-facing feature, in principle, and at these stages, and (b) that'll take some time to alter properly the mail state machine too.
We can add a "public" offline mode when smtp is also capable of offline operation, and we're able to do transitions between offline and online states (using the proxy object of soledad).
(from redmine: created on 2014-01-12, closed on 2014-01-13)