qt: Add option to (not) spend unconfirmed change

- Add a wallet tab to options dialog
- Move fee setting to wallet tab
- Add new setting to set -nospendzeroconfchange from UI

src/qt/optionsmodel.cpp

@@ -76,6 +76,11 @@ void OptionsModel::Init()
     nTransactionFee = settings.value("nTransactionFee").toLongLong(); // if -paytxfee is set, this will be overridden later in init.cpp
     if (mapArgs.count("-paytxfee"))
         strOverriddenByCommandLine += "-paytxfee ";
+
+    if (!settings.contains("bSpendZeroConfChange"))
+        settings.setValue("bSpendZeroConfChange", true);
+    if (!SoftSetBoolArg("-spendzeroconfchange", settings.value("bSpendZeroConfChange").toBool()))
+        strOverriddenByCommandLine += "-spendzeroconfchange ";
 #endif
 
     if (!settings.contains("nDatabaseCache"))
@@ -184,6 +189,8 @@ QVariant OptionsModel::data(const QModelIndex & index, int role) const
             // Todo: Consider to revert back to use just nTransactionFee here, if we don't want
             // -paytxfee to update our QSettings!
             return settings.value("nTransactionFee");
+        case SpendZeroConfChange:
+            return settings.value("bSpendZeroConfChange");
 #endif
         case DisplayUnit:
             return nDisplayUnit;
@@ -274,6 +281,12 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
             settings.setValue("nTransactionFee", (qint64)nTransactionFee);
             emit transactionFeeChanged(nTransactionFee);
             break;
+        case SpendZeroConfChange:
+            if (settings.value("bSpendZeroConfChange") != value) {
+                settings.setValue("bSpendZeroConfChange", value);
+                setRestartRequired(true);
+            }
+            break;
 #endif
         case DisplayUnit:
             nDisplayUnit = value.toInt();