* crc.pl: New file; perl script to do generate some test vectors

	* crc.pl: New file; perl script to do generate some test vectors
	and CRC tables.

	* CRC.pm: New file; perl module to implement CRCs in terms of
	polynomial arithmetic (verrrry slooow).

	* Poly.pm: New file; perl module to do polynomial arithmetic in
	the field of integers mod 2.

	* t_crc.c: New file; do some sanity checks (and timing checks,
	more useful when building shift-4 as well).

	* Makefile.in (check-unix): Add rules for building, running
	t_crc.

	* crc32.c (mit_crc32_shift4): Add new function, usually not
	compiled, for shift-4 implementation of CRC32.

	* crc-32.h: Add (conditionalized) prototype for the shift-4
	function; remove checksum_entry (it's no longer used).

	* crctest.c: Removed.

	* crc-test: Removed.

	* crc.c: Removed.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@14095 dc483132-0cff-0310-8789-dd5450dbe970