des_encrypt() and des_encrypt() defined on some systems (Solaris and
Unixware and maybe others), we rename des_encrypt() to des_encrypt1().
This should have very little impact on external software unless
someone has written a mode of DES, since that's all des_encrypt() is
meant for.
Never use des_set_key (it depends on the global variable des_check_key),
but usually des_set_key_unchecked.
Only destest.c bothered to look at the return values of des_set_key,
but it did not set des_check_key -- if it had done so,
most checks would have failed because of wrong parity and
because of weak keys.
