System Comparison Skeleton

This skeleton will read the CO$INSTALL$/COMUS$ elements of one or more
systems and produce 3 reports: 1) a list of all products installed on all
systems, showing their levels and modes; 2) a list of all products in
reverse chronological order; and 3) a list of all BDIs used on all systems.
     The skeleton is meant to be executed out of a file. If there is
nothing else in the file, it will default to creating the reports for the
current system. To have it run the reports for one more other systems,
you must:

1. Create the element SYSCOMP/SYSLIST in the same file as the skeleton.
   This element contains a single SGS line with the label SYS and the
   site names or abbreviations of the systems to be reported on. Example:
        SYS   SYS1 SYS2 DEV TEST
   Note that in the product list and BDI reports, the systems will be
   assigned sequence numbers based on their order on this image.

2. Copy the CO$INSTALL$/COMUS$ element out of the SYS$*DATA$ file from every
   system to be reported on into the same file as the skeleton, changing its
   name to CO$DATA/xxx, where xxx is the systems's site name or designation
   as it appears on the SYSCOMP/SYSLIST image.

Call the skeleton with "@SSG <file>.SYSCOMPSKEL", then enter @EOF. You will
see it produce the first two reports. Unless it received a hard EOF, it will
then query you as to the BDI report, which can take longer. Reply Y or N.
     The reports are placed in elements PRODLIST, PRODLIST/CHRON, and BDIS.