Investigate v3.0 mongos and v3.2 cluster compatibility issues in jstests/sharding

SERVER-21593 findAndModify on v3.0 mongos and v3.2 cluster can return stale config error to the user

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• Closed

SERVER-21603 getLastError does not wait for replication on mongos v3.0 with mongod v3.2

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• Closed

SERVER-21604 v3.0 mongos fails to ping config.mongos if config servers are v3.2

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• Closed

SERVER-21660 serverStatus can stall and trigger timeout error on SCCC distributed lock with v3.0 mongos and v3.2 cluster

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• Closed

SERVER-21661 v3.0 mongos and v3.2 cluster explain command are not compatible

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• Closed