User Access Logging to record X-Forwarded-For HTTP header

From CSP-37258:

I would also suggest adding another feature and improvement for AccessLogFilter to have it log X-Forwarded-For headers - this would produce more informative results when a reverse proxy is used in front of tomcat, as is in my case (all origin IPs are logged as '127.0.0.1' which is the proxy's IP address) and, I suppose, will be the case for most enterprise setups.