Feature/master/pe 945 update report format docs


    Document changes to report format (version 4)
    
    This commit introduces changes for version 4 of the
    puppet report format.  This particular commit is related
    to the addition of a `containment_path` attribute to the
    `resource_status` objects; however, there will probably
    be a few additional changes that can be rolled into v4
    in subsequent commits prior to the Puppet 3.3.0 release.