Added mkrep.sh script to create a replica.
This current version does most of the steps of creating a replica in
an SDP environment, benefitting from server spec naming standards and
conventions. It then provides guidance on the remaining steps
(e.g. transferring the checkpoint to the replica host, etc.)
It greatly distills the potential complexity of creating a repliac by
distilling the many potential replica types to just those few commonly
used, 'fr' (forwarding replica), 'ro' (read-only replica), and 'edge'.
The script is self-documenting with a '-h' (short usage) and '-man'
(detailed man page) options.
This first version is functional but is definitely a work in progress.
It will evolve as part of the HMS project, but this part lives
in the stock SDP.