Mark _rsa_blind and _rsa_unblind as deprecated.

ChangeLog

+2015-11-15  Niels Möller  <nisse@lysator.liu.se>
+
+	* rsa.h (_rsa_blind, _rsa_unblind): Mark as deprecated.
+
 2015-09-17  Niels Möller  <nisse@lysator.liu.se>
 
 	* rsa-md5-sign-tr.c (rsa_md5_sign_tr, rsa_md5_sign_digest_tr): New

rsa.h

@@ -483,6 +483,8 @@ _rsa_verify(const struct rsa_public_key *key,
 size_t
 _rsa_check_size(mpz_t n);
 
+/* _rsa_blind and _rsa_unblind are deprecated, unused in the library,
+   and will likely be removed with the next ABI break. */
 void
 _rsa_blind (const struct rsa_public_key *pub,
 	    void *random_ctx, nettle_random_func *random,