Use base58check to encode Zcash payment addresses, such that the first two bytes are "zc".

src/base58.h

@@ -20,6 +20,7 @@
 #include "script/script.h"
 #include "script/standard.h"
 #include "support/allocators/zeroafterfree.h"
+#include "zcash/Address.hpp"
 
 #include <string>
 #include <vector>
@@ -95,6 +96,17 @@ public:
     bool operator> (const CBase58Data& b58) const { return CompareTo(b58) >  0; }
 };
 
+class CZCPaymentAddress : public CBase58Data {
+public:
+    bool Set(const libzcash::PaymentAddress& addr);
+    CZCPaymentAddress() {}
+
+    CZCPaymentAddress(const std::string& strAddress) { SetString(strAddress.c_str(), 2); }
+    CZCPaymentAddress(const libzcash::PaymentAddress& addr) { Set(addr); }
+
+    libzcash::PaymentAddress Get() const;
+};
+
 /** base58-encoded Bitcoin addresses.
  * Public-key-hash-addresses have version 0 (or 111 testnet).
  * The data vector contains RIPEMD160(SHA256(pubkey)), where pubkey is the serialized public key.