Extra characters to be escaped

[topikito]

As of ElasticSearchs documentation (http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html#_reserved_characters) the characters '<' and '>' needs to be escaped. However, Lucene does not require this. I've checked out the Util class code and its not escaping those characters.

Yesterday, I had an issue on production server due to a '<' symbol in a query that was not escaped. How are we dealing with this scenario?

I've created my own escape function that adds these two symbols for now. I've also created a PR.