CSHARP-1094: Honor ReadPreference and MaxTime in MongoCursor Count and Size.
CSHARP-664: Deprecate MongoClient.GetServer() and remove MongoServer.Create() methods.
CSHARP-664: Converted some tests to use the new high level API instead of using #pragma to ignore the warning when GetServer is called.
CSHARP-664: Removed new extension method that was not worthy.
CSHARP-1074: Reimplement legacy MapReduce using an operation in Core. Add tests for MapReduceOperations.
removed timeout and refactored cancellation everywhere in Core except Operations.
removed timeout from operations and clarified the role of cancellation tokens in cursors and operations.