PROV-766 Don't try to reindex if change field array is set to an empty array (indicates no changes to index). Reindexing on empty changes doesn't carry a significant penalty in SqlSearch, which can do partial reindexing, but is costly with engines like SOLR where it triggers a whole-record reindex. This should (hopefully) resolve the timeout issues LIBIS and others have been experiencing.
Merge branch 'master' of github.com:collectiveaccess/providence