Create BackedupMapDataLossTest

Test case to validate nulls being returned by a distributed map on n/w disconnections, in a cluster of 3 nodes with backup count set to 3.
dsetroy map with map store test
dsetroy map with map store test
dsetroy map with map store test
dsetroy map with map store test
looping for .....
Fixed remote exception and added unittest to show this is already fixed
unit test fix for #3052 and #3053
Use Config created when creating Hazelcast instance
Moved impl classes of topic to impl package
Moved queue implementation classes to impl package
Fixed issue with topicservice.statsmap access
Added FutureUtil class to unify calls with multiple Future objects

Conflicts:
	hazelcast/src/main/java/com/hazelcast/util/ExceptionUtil.java
Merge pull request #3076 from serkan-ozal/fix/master/issue-3052-and-3053

unit test fix for #3052 and #3053
Removed some useless method overloads and lowered object allocation rate on ExceptionHandlers
Renamed test methods, fixed compile errors
fixes #3110
Merge branch 'master' of https://github.com/hazelcast/hazelcast
Improved IO threading model documentation
Modified Set documentation to include more details on partitioning and backup storage