re-work optionsdialog to a tabbed UI based on an ui-file

- extend network options with a SOCKS version selection
- changing "Unit to show amounts in:" now also updates the unit used in the transaction fee box
- string updates
- link Apply button and OK button when enabling or disabling them
- use LookupNumeric() from netbase to verify proxy address (via an EventFilter)
- change proxy address field to QValidatedLineEdit and add visual feedback
- add a status label used for displaying a message for invalid proxy addresses
- allow usage of IPv6 address as proxy address
- added warning message when enabling / disabling SOCKS proxy

src/qt/optionsmodel.cpp

@@ -20,6 +20,7 @@ bool static ApplyProxySettings()
     if (!settings.value("fUseProxy", false).toBool()) {
         addrProxy = CService();
         nSocksVersion = 0;
+        return false;
     }
     if (nSocksVersion && !addrProxy.IsValid())
         return false;
@@ -53,6 +54,8 @@ void OptionsModel::Init()
         SoftSetBoolArg("-upnp", settings.value("fUseUPnP").toBool());
     if (settings.contains("addrProxy") && settings.value("fUseProxy").toBool())
         SoftSetArg("-proxy", settings.value("addrProxy").toString().toStdString());
+    if (settings.contains("nSocksVersion") && settings.value("fUseProxy").toBool())
+        SoftSetArg("-socks", settings.value("nSocksVersion").toString().toStdString());
     if (settings.contains("detachDB"))
         SoftSetBoolArg("-detachdb", settings.value("detachDB").toBool());
     if (!language.isEmpty())
@@ -142,7 +145,7 @@ QVariant OptionsModel::data(const QModelIndex & index, int role) const
         case ProxyUse:
             return settings.value("fUseProxy", false);
         case ProxySocksVersion:
-            return settings.value("nSocksVersion", false);
+            return settings.value("nSocksVersion", 5);
         case ProxyIP: {
             CService addrProxy;
             if (GetProxy(NET_IPV4, addrProxy))
@@ -203,6 +206,10 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
             settings.setValue("fUseProxy", value.toBool());
             ApplyProxySettings();
             break;
+        case ProxySocksVersion:
+            settings.setValue("nSocksVersion", value.toInt());
+            ApplyProxySettings();
+            break;
         case ProxyIP:
             {
                 CService addrProxy("127.0.0.1", 9050);