ExecutionService improvements
MapStore changed to use single thread executor in order to prevent out of sync between MapStore and Map.
fixes #1595
cancel scheduled tasks when needed
fixes #1595
fix removing tasks
fixes #1595
fix removing tasks
Update file for pr build.
update file for pr build
Merge branch 'master' of https://github.com/hazelcast/hazelcast
fix removal of registered executor for map store
Adding Missing Spring 4 Cache Method

Spring 4 adds a method with signature:
public <T> T get(Object key, Class<T> type)
Merge branch 'master' of https://github.com/hazelcast/hazelcast
more findbugs fixes
Exception message returned as the result if there are any exception
Generic Error internal data changed
DataSerializable doesn't exist Serializable anymore
Merge pull request #1661 from pveentjer/findbugs

more findbugs fixes
Merge pull request #1662 from eminn/ScriptingErrorResponse

Script Execution will return exception message
Fixed possbile NPE; PartitionService.getPartitionOwner(pid) may return null.
Merge pull request #1628 from kjordan2001/patch-1

Adding Missing Spring 4 Cache Method
Merge pull request #1665 from asimarslan/feature/master/genericerror

Generic Error internal data changed