I have submitted a patch for Jira ticket NIFI-285 -- which is the task to
add a section on the System Properties to the Administrator's Guide.
As a side note, we really need to fill in the Security Configuration
section of this guide. I would need to work with someone else on this
section. In previous iterations, people generally found that stuff very
confusing, and if I write it on my own, it'll be like the blind leading the
blind. If anyone is willing to join forces, let me know!