Cleanup
Make MessageQueueTarget testable

And add tests
Handle queue using FormatName

Do not check if queue exists, if queue name uses FormatName prefix as this
is not supported by MessageQueue.Exists
Partly solves #124
Add CheckIfQueueExists to MessageQueueTarget

As it is very difficult to check if the queue is a remote private queue,
which is not supported by MessageQueue.Exists, we instead add a property
allowing the user to defined if we should check if the queue exists before
writing to it.
fixes #124
Merge branch 'Msmq' into umaster
Send exception information in NLogViewerTarget

No exception information is send with the NLogViewerTarget. This is fixed
by checking if exception information is present in the log event and write
to the XML.
fixes #129
Fix build error
Check if UserStackFrame is null

Sometimes the userstackframe can be null in Log4jXmlEventLayoutRenderer.
To avoid a NullReferenceException check of null, and continue.
fixes #146
Fix test error