Make the Kerberos 4 bits build against OpenSSL 0.9.7. This required
two basic changes (both of which should be no-ops until OpenSSL 0.9.7
is imported):

= Define OPENSSL_DES_LIBDES_COMPATIBILITY wherever we include

openssl/des.h.

= Spell `struct des_ks_struct []' using the existing

`des_key_schedule' typedef.

When OpenSSL 0.9.7 is imported, `des_key_schedule' (among other
things) will be a macro invocation instead of a typedef, and things
should `just work'.

Yes, this commit does take several files off the vendor branch.
I do not expect there to be future imports of KTH Kerberos 4.