count(), update(), bulkWrite(), abstract tree management and options ### Drivers - Added count() - Added countEstimated() - Added updateOne(), updateMany(), upsertOne() - Added findOneAndUpdate() - Added filtered collections - Added an 'options' lambda to all operations - Added CountOptions.limit() - Improved MongoCollection.toString() - Added bulkWrite() ### DSL - The BsonContext is now available in all expressions - Abstract over tree management with the new '.tree' package - Reorganize all operations from XXXExpressions to XXXOperators interfaces (to allow delegation) - Add Expression.toBsonDocument ### BSON - Added buildBsonArray ### Deployment - Added an integration test to ensure the driver is compatible with 3 stable MongoDB versions