Exported add operation for ge25519

configure.ac

 ## ExampleLib Example: an example of using Automake to link with a library
 
-AC_INIT([ED25519], [3:6], [bernd@net2o.de], [ed25519-donna],
+AC_INIT([ED25519], [3:7], [bernd@net2o.de], [ed25519-donna],
         [http://keccak.noekeon.org/])
 AC_PREREQ([2.59])
 AM_INIT_AUTOMAKE([1.10 -Wall no-define])

ed25519-donna-impl-base.h

@@ -119,7 +119,7 @@ ge25519_double(ge25519 *r, const ge25519 *p) {
 	ge25519_p1p1_to_full(r, &t);
 }
 
-static void
+STATIC void
 ge25519_add(ge25519 *r, const ge25519 *p,  const ge25519 *q) {
 	ge25519_p1p1 t;
 	ge25519_add_p1p1(&t, p, q);

ed25519-prims.h

@@ -27,6 +27,7 @@ typedef struct ge25519_niels_t {
 
 void ge25519_pack(unsigned char r[32], const ge25519 *p);
 int ge25519_unpack_negative_vartime(ge25519 *r, const unsigned char p[32]);
+void ge25519_add(ge25519 *r, const ge25519 *p,  const ge25519 *q);
 void ge25519_double_scalarmult_vartime(ge25519 *r, const ge25519 *p1, const bignum256modm s1, const bignum256modm s2);
 void ge25519_scalarmult_vartime(ge25519 *r, const ge25519 *p1, const bignum256modm s1);
 void ge25519_scalarmult(ge25519 *r, const ge25519 *p1, const bignum256modm s1);