Fix Elastic[S]earch case and add missing "use"

See https://github.com/elasticsearch/elasticsearch/issues/4634
about the official case of Elasticsearch versus ElasticSearch.
Merge pull request #597 from damienalexandre/cosmetic-case

Fix Elastic[S]earch case and add missing "use"
Prepare release v1.1.1.1
Add missing issue nubmers to changes.txt
Merge conflict in changes.txt file