Direct connections weren't working.
Fix bug in MongoServer tracking of replica set members.
created a new console app and created multiple versions of the same program via our different apis.
Caching the hashcodes of certain classes because DnsEndPoint's GetHashCode method seems excessively heavy.
added more exception types for immediate invalidation in ClusterableServer.
removed AsyncBackgroundTask and used async void methods to run background tasks.
removed AsyncBackgroundTask.
a little cleanup.
CSHARP-1145: listCollections now supports cursors.
CSHARP-1145: added support for cursors to list indexes.
BinaryConnection no longer uses background threads and instead eagerly and cooperatively processes sends and receives.