use "Metis_" prefix rather than "Metis" structure;
the prefix can then be used not only for structures but also signatures and functors. A few other changes were made to the script, to eliminate the need for "metis_env.ML".
#!/usr/bin/env bash
#
# rsync server start script
/usr/bin/rsync --daemon --config=/home/proj/isabelle/rsyncd.conf