CSHARP-713: MongoDatabase.Eval doesn't send argument to server when there is exactly one argument.
CSHARP-715: InsertBatch fails when large batch has to be split into smaller sub batches.
CSHARP-715: Add unit test for InsertBatch with small final subbatch.
CSHARP-717: Fix regression where reading from a socket that has been closed by the server is now hanging instead of throwing an EndOfStreamException.