correct calculation heapCost when record is evicting from DefaultRecordStore
Adds the CompletableFuture

This makes reactive programming possible. The InvocationImpl has been changed
so it returns a CompletableFuture instance which eventually can be exposed directly
to the end user.

Exposing it to the end user using e.g. AsyncQueue/AsyncAtomicNumber etc will be part
of other pull request.
CompletionFuture: the andThen can be configured with an executor
CompletableFuture: Extracted the BackupCompletionCallback to clean up Invocation interface
Renamed to CompletableFuture
CompletableFuture makes use of the AsyncExecutor
Working on review comments
fixes #1085
Dealt with the Interrupted exception
added @SpringAware for entryProcessors fixes #1228
Merge pull request #1275 from enesakar/master-terminating-services

fixes #1085
Merge branch 'issue1228-springaware-for-entryprocessor/3.x-master' of github.com:gurbuzali/hazelcast
Merged #1280
Merge pull request #1258 from krolser/fix-map-default-record-store-estimator-calculation

correct calculation heapCost when record is evicting from DefaultRecordS...
Merge branch 'improvement/3.x/completablefuture-basic-refactoring' of github.com:pveentjer/hazelcast
Merged #1234. Cleaned up op.async field. Cleaned up commented sections. Improved InvocationTest.
added record info for txnal put backup
Merge pull request #1285 from enesakar/master-fix-txnputbackup

added record info for txnal put backup
correct size estimation
size estimator test fixes