Job names are derived from job type + user-defined name in config file
CLI now has subcommands corresponding 1:1 to the config file sections:
push,pull,autosnap,prune
A subcommand always expects a job name, thus executes exactly one job.
Dict-style syntax also used for PullACL and Sink sections.
jobrun package is currently only used for autosnap, all others need to
be invoked repeatedly via external tool.
Plan is to re-integrate jobrun in an explicit daemon-mode (subcommand).
Pushing is achieved by inverting the roles on the established
connection, i.e. the client tells the server what data it should pull
from the client (PullMeRequest).
Role inversion is achieved by moving the server loop to the serverLoop
function of ByteStreamRPC, which can be called from both the Listen()
function (server-side) and the PullMeRequest() client-side function.
A donwside of this PullMe approach is that the replication policies
become part of the rpc, because the puller must follow the policy.
