Add Solaris support to ncm-cron.

This change involves:
o Adding a new variable securitypath to identify where the
cron.allow/deny files live
o Added processing to share crontab files with users on Solaris. This
is because Solaris uses an old version of cron.
o Solaris specific cron tests.
o Updated pan files for securitypath

The most interesting change involves the shared use of user crontabs. To
make this work ncm-cron uses the concept of separate file sections
within the crontab.  The ncm section is identified by the use of the
tags NCM-CRON BEGIN:and NCM-CRON END:. Entries either side of these
section identifiers are not modified.