Auto detect testnet and mainnet ports

src/settings.h

@@ -6,7 +6,8 @@
 class Settings
 {
 public:
-    Settings();
+    static Settings* init();
+    static Settings* getInstance();
 
     QString getUsernamePassword();
 	QString getHost();
@@ -15,8 +16,13 @@ public:
     void setDefaultPort(int port) {overridePort = QString::number(port);}
 
     double  fees() { return 0.0001; }
-	void    refresh();
+	void    loadFromSettings();
+    void    loadFromFile();
 private:
+    // This class can only be accessed through Settings::getInstance()
+    Settings() = default;
+
+    static Settings* instance;
 
     QString host;
 	QString port;