address win32 build issues

- Replace external -DOPENSSL/-DPKCS11CRYPTO with properly AC_DEFINEd
  HAVE_OPENSSL/HAVE_PKCS11
- Don't enforce the crypto provider from platform.h, just from dst_api.c
  and configure scripts

lib/isc/win32/socket.c

@@ -9,6 +9,8 @@
  * information regarding copyright ownership.
  */
 
+#include <config.h>
+
 /* This code uses functions which are only available on Server 2003 and
  * higher, and Windows XP and higher.
  *