backup_diff.sh, backup_full.sh: Cleaned up for publication, added rsync transfer...

- Moved hard-coded data to separate config file.

- Now it is configurable how to transfer backup files to a remote server:
it is possible by scp or rsync, or to not transfer them at all.
The backup directory may be mounted from a remote server by NFS or other method,
in which case there is no need to transfer the files by scp or rsync.

Note however, backup_full.sh purges the backup directory, because it is assumed
that the files have already been transferred to a remote location.

	modified:   fs/backup_diff.sh
	new file:   fs/backup_fsdiff.conf
	modified:   fs/backup_full.sh