Few fixes
Add a utilities to transform the successful/failed convention into S_OK/S_ERROR for the first element
refactor of SE
new class DataManager
fix rebase
Adapt DataManager class
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Fix conflict
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog

Conflicts:
	DataManagementSystem/Agent/RequestOperations/ReplicateAndRegister.py
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog
Replace ReplicaManager with DataManager, StorageElement and FileCatalog