Move generic circuit gadgets into bellman

zcash_proofs/src/sapling/prover.rs

@@ -1,11 +1,13 @@
-use bellman::groth16::{
-    create_random_proof, verify_proof, Parameters, PreparedVerifyingKey, Proof,
+use bellman::{
+    gadgets::multipack,
+    groth16::{
+        create_random_proof, verify_proof, Parameters, PreparedVerifyingKey, Proof,
+    },
 };
 use ff::Field;
 use pairing::bls12_381::{Bls12, Fr};
 use rand_os::OsRng;
 use sapling_crypto::{
-    circuit::multipack,
     jubjub::{edwards, fs::Fs, FixedGenerators, JubjubBls12, Unknown},
     primitives::{Diversifier, Note, PaymentAddress, ProofGenerationKey, ValueCommitment},
 };

zcash_proofs/src/sapling/verifier.rs

@@ -1,10 +1,10 @@
-use bellman::groth16::{verify_proof, PreparedVerifyingKey, Proof};
+use bellman::{
+    gadgets::multipack,
+    groth16::{verify_proof, PreparedVerifyingKey, Proof},
+};
 use ff::Field;
 use pairing::bls12_381::{Bls12, Fr};
-use sapling_crypto::{
-    circuit::multipack,
-    jubjub::{edwards, FixedGenerators, JubjubBls12, Unknown},
-};
+use sapling_crypto::jubjub::{edwards, FixedGenerators, JubjubBls12, Unknown};
 use zcash_primitives::{
     redjubjub::{PublicKey, Signature},
     transaction::components::Amount,