duplicated in cbc_enc.c (without IV updating) and in des_enc.c

As pointed out by others on the openssl-dev list, des_cbc_encrypt (without
IV updating; defined in cbc_enc.c) exists only for historical reasons:
des_ncbc_encrypt should be used instead (and the caller does not have
to manually update the IV).

If des_cbc_enrypt is not needed for backwards compatibility, the
definition of des_ncbc_encrypt should be put back into des_enc.c, and
both cbc_enc.c and ncbc_enc.c can be deleted.

If des_cbc_encrypt *is* needed for backwards compatibility, its behaviour
obviously should not change (i.e., don't add IV updating).

Pointed out by: Janez Jere <jj@void.si>

Allow configuring the name of that header file.

there is no system crypt() available.

Submitted by: Janez Jere <jj@void.si>

structure and decides what key to generate (if any). Not currently added to
the PBE algorithm list because it is largely untested.

a pain to read when using 4-space tabs.

so that the SSL library can be used for applications that
have to handle all the actual I/O themselves.

NeXTstep creates a directory called -p); now mkdir-p.pl does its job.

> The nextstep port uses the -O3 switch to gcc.  Support for -O3 didn't appear
> until later (and buggier) versions of NeXTstep.  Use -O instead, or have a
> separate port.

Submitted by: Mark Crispin <MRC@Panda.COM>

Submitted by: Christian Forster <fo@hawo.stw.uni-erlangen.de>

also for NeXT).