Fix BlackMisc header includes

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

refs #630

src/blackmisc/weather/gridpoint.cpp

@@ -11,6 +11,8 @@
 #include "blackmisc/propertyindex.h"
 #include "blackmisc/variant.h"
 
+#include <QtDebug>
+
 using namespace BlackMisc::Aviation;
 using namespace BlackMisc::Geo;
 using namespace BlackMisc::PhysicalQuantities;