Fix BlackMisc header includes

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

refs #630

src/blackmisc/timestampbased.cpp

@@ -7,10 +7,15 @@
  * contained in the LICENSE file.
  */
 
-#include "timestampbased.h"
 #include "blackmisc/comparefunctions.h"
+#include "blackmisc/timestampbased.h"
 #include "blackmisc/variant.h"
 
+#include <QByteArray>
+#include <QDate>
+#include <QTime>
+#include <Qt>
+
 namespace BlackMisc
 {
     ITimestampBased::ITimestampBased() : m_timestampMSecsSinceEpoch(QDateTime::currentMSecsSinceEpoch())