Remove crusty old "loadVerifyingKey"/"loadProvingKey" APIs and associated invariants.

src/zcash/GenerateParams.cpp

@@ -18,13 +18,7 @@ int main(int argc, char **argv)
     std::string vkFile = argv[2];
     std::string r1csFile = argv[3];
 
-    auto p = ZCJoinSplit::Generate();
-
-    p->saveProvingKey(pkFile);
-    p->saveVerifyingKey(vkFile);
-    p->saveR1CS(r1csFile);
-
-    delete p;
+    ZCJoinSplit::Generate(r1csFile, vkFile, pkFile);
 
     return 0;
 }