I have put back the CASTOR man page sections in the master branch.

The good news is that I have been able to remove the perl processing of the
CASTOR manual pages that was changing the simple numerical section numbers
into CASTOR specific ones.  Developers now just write their manual pages and
the Imake system will not change the man page section within them.  Therefore
if a manual page should be part of the 8castor man page section then the
developer should explicitly put 8castor in the .TH line and not just 8.  Being
explicit means the reader of the man source know what they will get.