When Monasca is enabled disable direct logging to ElasticSearch and
send all logs harvested by Fluentd to the Monasca Log API.
This change also cleans up output files which may be left behind when
the various log forwarding options are enabled / disabled.
Partially-Implements: blueprint monasca-roles
Change-Id: I7197966c5117176407d60c86c08d3bcea5e8131a