To simplify plugins maintenance and provide more value in the future, we are starting to build an `elasticsearch-parent` project. This commit is the first step for this plugin to depend on this new `pom` maven project.
We create branches:
* es-0.90 for elasticsearch 0.90
* es-1.0 for elasticsearch 1.0
* es-1.1 for elasticsearch 1.1
* master for elasticsearch master
We also check that before releasing we don't have a dependency to an elasticsearch SNAPSHOT version.
Add links to each version in documentation
(cherry picked from commit 65d4862)