Puppet: Improve scalability & versions

1) puppet-master.install: Add Passenger mode

This mode improves the scalability of Puppet
by running it with Apache2.

The puppet-master node will not run this mode by default
but prepare packages to run it.

The configuration of Passenger should be done by Puppet itself
when bootstraping.

2) openstack-swift roles: Use puppetlabs repository with the goal to
have recent releases.

Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>