fix transactional set duplicate element insertion.
ClientQueueTest clean up, and addedd new test
cleanup resources should be called within IO thread if client is shutting down
Merge pull request #2091 from eminn/fix/TxnSetDuplicateElement

fix transactional set duplicate element insertion.
quick-fix related PR #2091
Merge pull request #2092 from Danny-Hazelcast/Q1

ClientQueueTest clean up, and addedd new test
Merge pull request #2093 from gurbuzali/client-shutdown-fix/3.2-RC3

cleanup resources should be called within IO thread if client is shuttin...
3.2 release
3.2.1-SNAPSHOT