Merge branch 'hotfix/2.5.2'
avoid NPE when non-ISA rels but no ISA rels
updating poms for 2.5.3 release
updating poms for 2.5.3 release
Merge branch 'release/2.5.3'
Merge branch 'release/2.5.3' into develop
update pom versions for 2.6.0-SNAPSHOT development
Merge branch 'master' of ssh://stash.csiro.au:7999/sno/ontology-core into develop