Redundant methods in JobExplorer/JobInstanceDao APIs

[fmbenhassine]

As of v5.2, the JobExplorer/JobInstanceDao APIs contain two similar methods:

List<JobInstance> getJobInstances(String jobName, int start, int count);

List<JobInstance> findJobInstancesByJobName(String jobName, int start, int count);

Both methods return the same result. findJobInstancesByJobName is not used and should be deprecated in v6.0 for removal in v6.2.