[cvs-nhc98] patch applied (hat): In the basic Hat C routines:

Wed May 1 06:51:58 PDT 2002 malcolm * In the basic Hat C routines: * Use the ErrorMessage pointer in the .hat header to distinguish between _|_ and ^C. * Open the .hat.bridge file at the same time as the .hat file, and add error checking on the header, filesize, etc. * Fix a couple of bugs where routines forgot to check for a FileOffset in the range 0-4 (Root..Lambda) M ./src/hattools/artutils.c -12 +54