@Override
    public Boolean setJobEnabled(final String jobName, final boolean enabled) {
        modifyCluster(jobName, enabled);
        return Boolean.TRUE;
    }
Sets the enabled flag for a job with this name on all nodes in the
cluster.

@param jobName The name of the job to change the enabled state of.
@param enabled The value of the enabled flag.
@return True if successful.
stroom-job/stroom-job-impl/src/main/java/stroom/job/impl/JobManagerImpl.java