
Under VC++ _DLL is set to indicate that the application
will be linked against the DLL runtime library. It is
automatically set when /MD is used.

As a result OpenSSL shouldn't use _DLL to determine if
it should set OPENSSL_OPT_WINDLL because this will
cause linkage conflicts with static builds which do
include the /MD compiler switch.

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl