Roles and capabilities declare, templates run declared steps, reconcilers
stay free of I/O. POSIX host readers, the SSH exec transport and the
privilege layer move to a new package, napalm-unix. SNMP polling, ping
sweeps, discovery scoring, guest profiles, display labels and warnings
belong to the application; drivers declare SNMP OIDs as data and report
facts. Fixes become templates whose values come from the caller.
Says in which order this happens and where the open proposals #8-#14 and
#22 go instead.
