Deprecated StringRangeSet.

JAVA-1454
In MongoClientOptions, deprecated heartbeatConnectRetryFrequency in favor of minHeartbeatFrequency in order to comply with the server monitoring specification.

JAVA-1469
In MongoClientOptions, deprecated heartbeatThreadCount as it is no longer configurable.

JAVA-1478
Mechanism properties for MongoCredential are now case-insensitive

JAVA-1462