Deprecate the recursive includes of bn.h from various API headers (asn1.h,

dh.h, dsa.h, ec.h, ecdh.h, ecdsa.h, rsa.h), as the opaque bignum types are
already declared in ossl_typ.h. Add explicit includes for bn.h in those C
files that need access to structure internals or API functions+macros.

crypto/ecdsa/ecs_ossl.c

@@ -59,6 +59,7 @@
 #include "ecdsa.h"
 #include <openssl/err.h>
 #include <openssl/obj_mac.h>
+#include <openssl/bn.h>
 
 static ECDSA_SIG *ecdsa_do_sign(const unsigned char *dgst, int dlen, 
 		EC_KEY *eckey);