switched printfn to a Debug.WriteLine, we dont want the release version doing printfn
Added Debug.WriteLine information around the findMonoDocProviderForEntity, added a function to catch errors coming from helpTree.GetHelpXml and wrame with None|Some.  This was causing MonoDevelop to terminate with a unhandled exception.  Ideally GetHelpXml should be addressed to return the correct documentation is possible, I notice that GetHelpXml is marked as obsolete too