Central Collector in OpenShift (PR #774)

[Robin Roos]

Hi Trask,

I created a PR some time back to resolve issues in starting Central Collector within OpenShift.  

This PR allows Central Collector to run when the user is not root but is a member of the root group.

I'd really like to see that merged because we are having to maintain forks just for OpenShift deployment.

Kind regards, Robin.

https://github.com/glowroot/glowroot/pull/774