Make use of this wonderful modern C construct known as a `switch', instead of
8-line if() tests.
remove unused, private version strings except SSL_version_str

Also remove unused des_ver.h, which exports some of these strings, but is not installed.

ok miod@ tedu@
cast ASN1_STRING (unsigned char *) to match strlcat's argument (char *)

ok beck@
tedu the SSL export cipher handling - since we do not have enabled export
ciphers we no longer need the flags or code to support it.

ok beck@ miod@