added null check for addAllInternal()
added test
fixed checkstyle
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Merge branch 'master' of https://github.com/hazelcast/hazelcast
rebased and made some corrections
fixed failed test and solve merge conflicts
fix merge conflicts
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Topic Configuration section mostly completed.

Also, the updates in EP reviewed.
note potential concurrency pitfall when using write-behind map store.
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Fixed spurious failing Condition.await test
Minor conditiontest await timoeout cleanup
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Merge pull request #3337 from hasancelik/fixes#3330

added null check for addAllInternal() , added test
solved merge coflicts