Fix BlackMisc header includes

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

refs #630

src/blackmisc/pq/measurementunit.cpp

@@ -9,6 +9,7 @@
 
 #include "blackmisc/pq/measurementunit.h"
 #include "blackmisc/math/mathutils.h"
+#include <QLocale>
 
 using namespace BlackMisc::Math;