Add CashAddr Address Format

Ported from Bitcoin Unlimited, Bitcoin ABC

src/dstencode.cpp

@@ -0,0 +1,33 @@
+// Copyright (c) 2017 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+#include "dstencode.h"
+#include "base58.h"
+#include "cashaddrenc.h"
+#include "chainparams.h"
+#include "config.h"
+#include "script/standard.h"
+
+std::string EncodeDestination(const CTxDestination &dst, const CChainParams &params, const Config &cfg)
+{
+    return cfg.UseCashAddrEncoding() ? EncodeCashAddr(dst, params) : EncodeLegacyAddr(dst, params);
+}
+
+CTxDestination DecodeDestination(const std::string &addr, const CChainParams &params)
+{
+    CTxDestination dst = DecodeCashAddr(addr, params);
+    if (IsValidDestination(dst))
+    {
+        return dst;
+    }
+    return DecodeLegacyAddr(addr, params);
+}
+
+bool IsValidDestinationString(const std::string &addr, const CChainParams &params)
+{
+    return IsValidDestination(DecodeDestination(addr, params));
+}
+
+std::string EncodeDestination(const CTxDestination &dst) { return EncodeDestination(dst, Params(), GetConfig()); }
+CTxDestination DecodeDestination(const std::string &addr) { return DecodeDestination(addr, Params()); }
+bool IsValidDestinationString(const std::string &addr) { return IsValidDestinationString(addr, Params()); }