* des-compat.c: Added libdes typedef:s. Had to remove all use of

const in the process.
(des_check_key): New global variable, checked by des_set_key.

* des-compat.c (des_cbc_cksum): Implemented.
(des_key_sched): Fixed return values.

Rev: src/nettle/des-compat.c:1.4
Rev: src/nettle/des-compat.h:1.7