CSHARP-790: Add support for MaxTime to FindOne. Also added support for other options to FindOne like Fields, Skip and SortBy.
CSHARP-790: Optimize for the generic version of FindOneAs and only use reflection for the non-generic version.
Merge branch 'csharp790findone' into csharp790failpoint

Conflicts:
	MongoDB.DriverUnitTests/MongoCollectionTests.cs
CSHARP-790: Fix unit tests.