At the end, stage-out in root installation was never implemented, so this merge request does it:
Stage-in (and waiting until copy happens, bool in trasfer_datasets)
Stage-out (and waiting until copy happens)
terminates adhoc fs
removes adhoc fs directory.
Some issues with needed environment variables solved, however LIBGKFS_HOSTS_FILE and GKFS_DAEMON and GKFS_CLIENT should be defined in the environment as they are installation dependant.
