moved into it from unpack handler.  Done by Kevin P. Fleming.
#   Makefile - Makefile for common code library.
*  digest.c - Verify a file's contents have not been changed.
*  digest.h - Verify a file's contents have not been changed.
*  md5.c - MD5 (RFC 1321) sum computation.
*  md5.h - MD5 (RFC 1321) sum computation.