[v6r12] Some fixes

CHANGE: new pilot script renamed to dirac-pilot.py, old - to dirac-pilot-1.py
CHANGE: DataManager - removed removeCatalogFile() and dirac-dms-remove-catalog-file adjusted
NEW: ProcessMonitor - added evaluation of the memory consumed by a process and its children
NEW: JobWrapper, Watchdog - monitor memory consumption by the job ( in a Warning mode )