This allows the system to converge during corner cases where there is an
error, or when there are no remotes being used, but we are using the
--no-watch variable.
I deliberately left this in as a separate commit instead of rebasing
into the remote execution development branch because the placement of
the Unregister() and semaphore.V(1) were quite subtle and easy to forget
about.
This patch extends the --converged-timeout argument so that when used
with --remote it waits for the entire set of remote mgmt agents to
converge simultaneously before exiting.
purpleidea says: This particular part of the patch probably took as much
work as all of the work required for the initial remote patches alone!
This is a new mode to be used for bootstrapping mgmt clusters or in
situations with tight operational restrictions.
This includes the basics, additional functionality will follow!
