Added the AtomicLong GetOperation

The advantage of this class instead of relying on the AddAndGet is that the former doesnt
need to wait on backups and the latter does, so it will be more response and also cause
less load on the network and the backup member.
Merge pull request #1223 from pveentjer/improvement/3.x/atomiclong-get-operation

Added the AtomicLong GetOperation