Fix merging the merge result of a merge where at least one of the sets had x/mrefs
Merge pull request #1972 from bartcharbon/master

Fix merging the merge result of a merge where at least one of the sets h...
Merge pull request #1968 from dennishendriksen/master

Add unit tests for Elasticsearch batch search + fix FindBugs issues
Merge branch 'master' of https://github.com/molgenis/molgenis