FIX: FTSRequest adapted to use FTSJob and FTSFile, to be used by
dirac-dms-fts... commands
FIX: set error into opFiles
Merge pull request #2183 from phicharp/v6r11-FixFTS-141120

[v6r11]: FTSRequest adapted to use FTSJob and FTSFile
v6r11p23
Conflicts resolved with rel-v6r11
v6r12p4
Merge remote branch 'upstream/rel-v6r12' into rel-v6r12

Conflicts:
	DataManagementSystem/Client/FTSJob.py
	DataManagementSystem/Client/FTSRequest.py
	DataManagementSystem/scripts/dirac-dms-fts-monitor.py