ISPN-3868 Deadlock in RemoteCache getAsync

* changed interface NotifyingNotifiableFuture, implemented in NotifyingFutureImpl
* using futures from infinispan-commons (both RemoteCacheImpl and CacheImpl via LegacyNotifyingFutureAdaptor)
* reflected API changes to RpcManagerImpl, DistributedExecutorService and MapReduceTask

https://issues.jboss.org/browse/ISPN-3868