Make debug messages conditional.

You can swich it on/off via defining ADS_DEBUG_PRINT
By default massages wouldn't be printed.

src/DockWidget.cpp

@@ -224,7 +224,7 @@ CDockWidget::CDockWidget(const QString &title, QWidget *parent) :
 //============================================================================
 CDockWidget::~CDockWidget()
 {
-	qDebug() << "~CDockWidget()";
+    ADS_PRINT("~CDockWidget()");
 	delete d;
 }