policy.json: Allow one to manage them from the puppet module

This commit allow a deployer to manage the policies via this module
It relies on augeas to change only the policy needed. The init takes
a hash of policies and apply them.

Change-Id: I413702d5baa0e96c43f9a599e1e06ed23ab23993
Added metadata lint and puppet-syntax gems

metadata-json-lint is a little tool to check the validity of
Puppet metatdata.json files.

puppet-syntax tool check the validity of templates,manifests and hiera
files (the goal here is to replace manual checks in the gate by a
standard? check `rake syntax`).

Change-Id: I60b9cdfe27eeb8a8f5ad3a238dd847ed3096cb6b
Merge "policy.json: Allow one to manage them from the puppet module"
Merge "Added metadata lint and puppet-syntax gems"