This change implements SASL authentication in the Kafka chart.
Kafka and Exporter credentials are defined in the endpoints section,
while other credentials for producers and consumers can be defined
in the jaas section.
Additionally, a few server settings are provided to enable SASL auth,
and a jvm_options key is introduced. Any options specified here will
be set when starting Kafka, including the location of the jaas file
in this case.
Change-Id: I43469c5bb5734b62cf69be924fe9cf7078e82a9c
472097d7eb