Ongoing work on replication
Working version of replication.

Requires much needed cleanup and unit tests!!!
Fix bug which prevent reming replication after subscriber node restart
Configurable replication rate + lower log level

Also temporary removed safeguards that prevent replication from non master service member.
Added metrics
Configuration to disable strict replication source (strict = master + tx logs enabled)
Code review cleanup
Reset subscriptions map when terminating the manager.
Cleanup + new TODOs following peer review
Merge pull request #134 from wajam/manu-replication

Replication is working!!!