Rework login to take advantage of other clients logging in
Previously the Overseer entirely shut down operations when it noticed
that the user needed to login. This is all well and good if you only use Pulse,
but less helpful if use other clients too.
This change introduces a new timer that attempts ‘p4 login -s’ every few seconds to see if
there is a valid ticket. This is not unlike the timer that gets enabled when a connection is
lost.
This change also includes some WIP on submit support that I was too lazy to pull out.