Do not start packages on installation

The reason to not start packages on installation is to allow to configure
them before starting up (setting heap, cluster.name etc)

Also the documentation was updated in order to show, which statements need
to be executed to start up elasticsearch and configure it to fire up automatically on boot.
In addition, these statements are also printed out when the package is
installed, depending on whether chkconfig, system or update-rc.d is used.

Closes #3722