Mesos Master authentication config

[sadovnikov]

• aclJson should be prefixed with a comment
• possibly, authenticate is not necessary: having not-null aclJson is enough to indicate necessity to authenticate

Default config element

    master {
        aclJson = null
        authenticate = false
        imageName = "containersol/mmesos-master"
        imageTag = "# derive from mesos version"
        loggingLevel = "# INHERIT FROM CLUSTER"
    }