fixing syntax error
updates to work with the Sept 2013 version of logical replication
make the walsender status a property of the node not the path
add functionality so a new remoteWALListener pulls any older events
from sl_event using the code in remote_listener via a normal connection.

This ensures that events created before the INIT REPLICATION command will
still be processed.
add an option to init cluster and store node to mark a node as logical
send the last saved wal position on a START REPLICATION instead of 0