Add initial, mostly stub implementation of core replication code.
Add model for replication.
Bugfix: snapshots must be readonly by default/definition.
Update cli to support replication.
Implement initial version of replication API.
implement cli sub console for replication.
Merge branch 'master' into issue#215
Update share model for replica shares.
Enhance replication scheduler to use a single queue to be shared with all
senders to pipe messages from them to publish to different subscribers.
Refactor replica sender and receiver code for more robustness
don't use communicate for already finished processes to read stdout, err.
Merge branch 'master' into issue#215
Merge pull request #231 from schakrava/issue#215

Issue#215