Add translator for Elasticsearch

Elasticseach is an open source search server based on Lucene.

Use case would be similar to that of SOLR. There is a (slightly outdated) comparsion between the two here: http://solr-vs-elasticsearch.com/.

Java API docs are here: http://www.elasticsearch.org/guide/en/elasticsearch/client/java-api/current/index.html

Filter DSL documentation is here: http://www.elasticsearch.org/guide/en/elasticsearch/client/java-api/current/index.html

JBoss EAP 6 module docs: http://www.elasticsearch.org/guide/en/elasticsearch/client/java-api/current/_deploying_in_jboss_eap6_module.html

It supports several types of spatial filters:

• Bounding box
• Polygon
• Shape - This is based on JTS; I think the difference between this and Polygon is this allows options like WITHIN/INTERSECTS/DISJOINT.