clean away old VMS cruft

The old building scripts get removed, they are hopelessly gone in bit
rot by now.

Also remove the old symbol hacks.  They were needed needed to shorten
some names to 31 characters, and to resolve other symbol clashes.
Because we now compile with /NAMES=(AS_IS,SHORTENED), this is no
longer required.

Reviewed-by: Rich Salz <rsalz@openssl.org>