Merge branch 'beta' into mergemaster

# Conflicts:
#	src/main.cpp

src/zcash/Address.cpp

@@ -12,12 +12,20 @@ uint256 PaymentAddress::GetHash() const {
     return Hash(ss.begin(), ss.end());
 }
 
-uint256 ViewingKey::pk_enc() {
+uint256 ReceivingKey::pk_enc() const {
     return ZCNoteEncryption::generate_pubkey(*this);
 }
 
+PaymentAddress ViewingKey::address() const {
+    return PaymentAddress(a_pk, sk_enc.pk_enc());
+}
+
+ReceivingKey SpendingKey::receiving_key() const {
+    return ReceivingKey(ZCNoteEncryption::generate_privkey(*this));
+}
+
 ViewingKey SpendingKey::viewing_key() const {
-    return ViewingKey(ZCNoteEncryption::generate_privkey(*this));
+    return ViewingKey(PRF_addr_a_pk(*this), receiving_key());
 }
 
 SpendingKey SpendingKey::random() {
@@ -25,7 +33,7 @@ SpendingKey SpendingKey::random() {
 }
 
 PaymentAddress SpendingKey::address() const {
-    return PaymentAddress(PRF_addr_a_pk(*this), viewing_key().pk_enc());
+    return viewing_key().address();
 }
 
 }