Auditing and logging about nhin-d HOT 3 CLOSED

After a bit of investigation, I believe we'll go with nLog 
(http://nlog-project.org/) and isolate the implementation with our own 
interface so that it can be swapped out in other implementations. nLog has the 
advantage that it's released with the BSD license vs. log4net which uses the 
Apache 2.0. In any case the severity levels are similar (trace, debug, info, 
warning and error). I would suggest that Audit is not a severity level but a 
different cross-cutting concern. We should think about using a dependency 
injection container to make the swappable parts configurable after deployment.

Implementing a project that uses nLog for the logging implementation. I'll drop 
the interface and factory method into nhinCommon.

Wasn't able to drop this into nhinCommon as there is a reference to dnsResolver 
and I didn't want to pull that over to the XDS solution.