Made org.mongodb.QueryBuilder implement ConvertibleToDocument
added toString method to MongoClientOptions
Make ServerCursor final and Serializable
Added typed getters for Document class
Piggybacking getLastError command on to the write message's output buffer.  This is a longstanding request.
Piggybacking getLastError command on to the write message's output buffer for async implementation.  This is a longstanding request.
Added TODO on @Ignored test