[ICD] Standard configuration (uid/gid/NFS) of summit ICS hosts

from github@ics_doc

At summit, most of all ICS hosts are supposed to mount one NFS storage for saving data, e.g. FITS image from [BR]CU, log files, archived data. We need to define standard configuration on them.

fmadec cloomis if you have any preference on uid issue, comment here.

Just to keep the reference configuration both visible and updatable, I'll add what we are using to this description. Obviously this will become a proper doc sometime, somewhere.

1. Due to Subaru LDAP constraints, the pfs user has user and group IDs of 2085 (NOT 1000 as we had earlier)
2. All operational PFS hosts mount /software and /data
3. All operational software must run from /software
4. All data files must be written to /data
5. All MHS software must be run by the pfs user for operations, and by the developer for development.
6. Image files will be written by the pfs-data user (uid/gid 2087) for the actors which write into /data]
7. All users must have their own group ids, be in the pfs group, and have a umask of 002.
8. All shared directories must be group pfs and have g+rwx.