Fix BlackMisc header includes

* Include only what is used
* Use forward declaration when possible
* Sorted includes

refs #630

src/blackmisc/weather/weatherdataplugininfo.cpp

@@ -7,7 +7,10 @@
  * contained in the LICENSE file.
  */
 
-#include "weatherdataplugininfo.h"
+#include "blackmisc/weather/weatherdataplugininfo.h"
+
+#include <QJsonValue>
+#include <QtGlobal>
 
 using namespace BlackMisc;