Prepare branch es-1.x and es-1.4
Update release tool

(cherry picked from commit 24d2eb2)
Update to elasticsearch 1.4.0

As elasticsearch 1.4 will use Groovy as a default language, we need to keep compatibility for `mvel` users.

Closes #2.
Closes #4.

(cherry picked from commit c44254c)
Update to elasticsearch 2.0.0