Added estimatesmartfee function

Author: bahadirbb

src/bitcoinapi/bitcoinapi.cpp

@@ -406,6 +406,17 @@ double BitcoinAPI::estimatefee(int blocks) {
 	return result.asDouble();
 }
 
+smartfee_t BitcoinAPI::estimatesmartfee(int blocks) {
+	string command = "estimatesmartfee";
+	Value params, result;
+	smartfee_t ret;
+	params.append(blocks);
+	result = sendcommand(command, params);
+	ret.feerate = result["feerate"].asDouble();
+	ret.blocks = result["blocks"].asInt();
+	return ret;
+}
+
 string BitcoinAPI::signmessage(const std::string& bitcoinaddress, const std::string& message) {
 	string command = "signmessage";
 	Value params, result;

src/bitcoinapi/bitcoinapi.h

@@ -65,6 +65,7 @@ class BitcoinAPI
     void keypoolrefill();
     bool settxfee(double amount);
     double estimatefee(int blocks);
+    smartfee_t estimatesmartfee(int blocks);
 
     std::string signmessage(const std::string& bitcoinaddress, const std::string& message);
     bool verifymessage(const std::string& bitcoinaddress, const std::string& signature, const std::string& message);
@@ -83,7 +84,7 @@ class BitcoinAPI
 
     std::vector<accountinfo_t> listreceivedbyaccount(int minconf = 1, bool includeempty = false);
     std::vector<addressinfo_t> listreceivedbyaddress(int minconf = 1, bool includeempty = false);
-
+    
     gettransaction_t gettransaction(const std::string& tx, bool watch);
     std::vector<transactioninfo_t> listtransactions();
     std::vector<transactioninfo_t> listtransactions(const std::string& account, int count = 10, int from = 0);

src/bitcoinapi/types.h

@@ -210,6 +210,11 @@
 
 
 	/* === Other === */
+
+	struct smartfee_t{
+		double feerate;
+		int blocks;
+	};
 	struct utxoinfo_t{
 		std::string bestblock;
 		int confirmations;