disable Sun divison algorithm by default

CHANGES

@@ -120,9 +120,11 @@
 
      bntest.c has additional tests for binary polynomial arithmetic.
 
-     Two implementations for BN_GF2m_mod_div() are available (selected
-     at compile-time).  ...
-TBD ... OPENSSL_NO_SUN_DIV ...  --Bodo
+     Two implementations for BN_GF2m_mod_div() are available.
+     The default algorithm simply uses BN_GF2m_mod_inv() and
+     BN_GF2m_mod_mul().  The alternative algorithm is compiled in only
+     if OPENSSL_SUN_GF2M_DIV is defined (patent pending; read the
+     copyright notice in crypto/bn/bn_gf2m.c before enabling it).
 
      [Sheueling Chang Shantz and Douglas Stebila
      (Sun Microsystems Laboratories)]

crypto/bn/bn_gf2m.c

@@ -613,7 +613,7 @@ int BN_GF2m_mod_inv_arr(BIGNUM *r, const BIGNUM *xx, const unsigned int p[], BN_
 	}
 
 
-#ifdef OPENSSL_NO_SUN_DIV
+#ifndef OPENSSL_SUN_GF2M_DIV
 /* Divide y by x, reduce modulo p, and store the result in r. r could be x 
  * or y, x could equal y.
  */