we're doing something that shouldn't be done, that is relying on private
methods of the imap server implementation.

until I get to cleanup properly and submit patches for the several things
we're patching in the imap server implementation, keeping up with the
evolution of the imap server implementation is the only thing to do.

specially when we want to get 0.10 out of the door asap.

node-mail chokes if we don't.

I changed most of the logger statements to use a class attribute, in
this way it's easier to identify which class it's logging them.

in some cases I leave a module-level logger, when we're either using
functions or when the module it's too small.

at the same time I did a general review and cleanup of the logging
statements.