Return to owm weather provider

Since yahoo support already exists, so I've added new option
X-AW-Provider (apiver 3). Added tests for these cases

sources/test/testextweather.h

@@ -34,12 +34,14 @@ private slots:
     void cleanupTestCase();
     // test
     void test_values();
-    void test_run();
+    void test_runOWM();
+    void test_runYahoo();
     void test_ts();
     void test_image();
     void test_copy();
 
 private:
+    void run();
     ExtWeather *extWeather = nullptr;
     QString city = QString("London");
     QString country = QString("uk");