The file will not be queued for archival, but the Frontend will return
SUCCESS to allow zero-length files to be created in the namespace.

the Catalogue

Changes VERSION to VERSION_CMD to avoid name clash with EOS VERSION
macro.

Adapted the cta-admin commands so that we can set the --reason and the
--comment

CLOSEW

address on EOS

Removed diskInstance attiribute from the common::dataStructures::StorageClass class
Adapted unit tests
Adapted cta-admin commands

StorageClass now belongs to a VO (madatory)
Adapted unit tests
Modified cta-admin command to set the VO of a Storage Class

Added UNIQUE constraint on STORAGE_CLASS_NAME and removed the the UNIQUE constraint on DISK_INSTANCE_NAME and STORAGE_CLASS_NAME

cta.archivefile.max_size_gb 1000

Specifies maximum file size that the CTA Frontend will accept to queue
for archival. Defaults to 2 TB and can be configured in in increments
of 1 GB.

This storage class is ignored during CREATE, so that we don't need to
set up an archive route just for testing.

This decouples the "cta-admin tf ls" command from looking up path names
in the catalogue, paving the way to remove the path from the DB.

1. Needs to be sys.* so users can't change it
2. Should not be confused with sys.retrieve.req_id

Renames CTA_ArchiveFileID to sys.archive.file_id
Renames CTA_StorageClass to sys.archive.storage.class

Wrong parameter was passed as retrieve request id.
Added logs to frontend.
Implemented validation of cancel in archive retrive test (no file should be retrieved).

Also improved function name to better match XRootd names.

The retrieve request address is now stored in the EOS namespace as an extended attribute and deleted
after checks on cancellation. The cleanup of the queues will be eventually done by the tape servers.

Google protobuf3 logs a FATAL error if .at() is called for a
non-existent key, so the log is filled with errors if we use try {}
catch(...) {}