Fix BlackMisc header includes

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

refs #630

src/blackmisc/pq/time.h

@@ -14,6 +14,14 @@
 
 #include "blackmisc/blackmiscexport.h"
 #include "blackmisc/pq/physicalquantity.h"
+#include "blackmisc/pq/pqstring.h"
+#include "blackmisc/pq/units.h"
+
+#include <QList>
+#include <QMetaType>
+#include <QString>
+
+class QTime;
 
 namespace BlackMisc
 {