objects) or OPENSSL_BUILD_SHLIBSSL (for files that end up as libssl
objects) is defined, redefine OPENSSL_EXTERN to be OPENSSL_EXPORT.
This is actually only important on Win32, and can safely be ignored in
all other cases, at least for now.
authenticated attributes: this is used to retain the
original encoding and not break signatures.
Support for a SET OF which reorders the STACK when
encoding a structure. This will be used with the
PKCS7 code.