WIP: Graylog - needs testing
This adds Graylog, which consists of Graylog itself, Elasticsearch and Mongo DB. I'm not sure if what i've done with pwsecret and graylog_root_pw is TheRightThing™. I see an elk stack has been merged, maybe graylog and mongo can be merged with it? since elasticsearch is chared, and Kibana can Graph data from Graylog...
I have added a few instructions to docs too, but Markdown is not my thing either....
Edited by Rob Loranger