Misc networking fixes

- connecting to nodes is much faster and more reliable now
- reduced the amount of spaghetti in libwalletqt and greatly simplified the logic in nodes.cpp
- Settings -> Node dialog should feel slightly more responsive
- during synchronization the status bar will now display the amount of data downloaded
- fixed some edge cases that could cause unreasonably long hangs
- Help -> Debug Info screen now auto-updates every 5 seconds
- Don't use SSL over Tor

src/model/NodeModel.cpp

@@ -70,9 +70,9 @@ QVariant NodeModel::data(const QModelIndex &index, int role) const {
     }
     else if(role == Qt::BackgroundRole) {
         if (node.isConnecting)
-            return QBrush(QColor(186, 247, 255));
+            return QBrush(QColor("#A9DEF9"));
         else if (node.isActive)
-            return QBrush(QColor(158, 250, 158));
+            return QBrush(QColor("#78BC61"));
     }
     return QVariant();
 }