Fixed regression in SimplePool
Collapsed MongoConnectionStrategy into MongoMultiServerBinding.  It wan't pulling enough weight, and it's making it difficult to add support for refreshing replica set state on a socket exception.
Renamed MongoConnectionManager to MongoServer (and all subclasses similarly renamed).
Renamed Node to ServerDescription
Renamed ReplicaSet to ReplicaSetDescription
More refactoring of replica set monitor.  Now each DefaultMongoServer instance is responsible for keeping its own state up to date, which it will need to do anyway for single server and mongos set binding types.  Additionally it provides the ability for client to register listeners for change events  ReplicaSetMonitor has been folded in to ReplicaSetServerBinding, and simply adds itself as a listener to each DefaultMongoServer instance.