rescheduled inflight pushes + events not in cache

With high volume repos, it is possible for Gerrit to re-schedule a replication
due to an inflight push. This re-schedule will result in a failed replication state
and will result in a failed build. By only proceeding on a successful replication
status, this will be avoided.

This commit also includes a fix to cope with missed events due to a Jenkins restart
Improve help for draft published

Added a warning note for the usage of Draft Published events
when using Replication Events. The note is only seen when replication
is configured at the admin level.

Upgraded to gerrit-events 2.4.2
Merge pull request #188 from scoheb/replication-fixes

Reschedule inflight pushes and help improvements for draft published