Added distribution management configuration using variables

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>
Update play to 2.1.1

Change all integration-tests
Update documentation (quickstart)

Also change the documented phase of the install-play goal. pre-clean is probably not what we wanted, using validate instead.

Signed-off-by: Clement Escoffier <clement.escoffier@gmail.com>