Cleanup: remove parameter from currentDiveChanged signal

The currentDiveChanged signal was emitted by the DiveListView
to inform the MainWindow of a change of current dive. The
new current dive was passed as a parameter. The slot in MainWindow
then called select_dive() on the dive.

This seems pointless because:
1) In both emits, selected_dive dive was passed as argument. But
   MainWindow can read this global variable itself.
2) Calling select_dive() again is a no-op, because obviously,
   this already *was* the selected dive.

Moreover it seems conceptually wrong to set the current dive in the
slot that is informed of the change of the current dive.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

desktop-widgets/starwidget.cpp

@@ -57,7 +57,7 @@ void StarWidget::mouseReleaseEvent(QMouseEvent *event)
 	else
 		current = starClicked;
 
-	Q_EMIT valueChanged(current);
+	emit valueChanged(current);
 	update();
 }
 
@@ -88,7 +88,7 @@ void StarWidget::setCurrentStars(int value)
 {
 	current = value;
 	update();
-	Q_EMIT valueChanged(current);
+	emit valueChanged(current);
 }
 
 StarWidget::StarWidget(QWidget *parent, Qt::WindowFlags f) : QWidget(parent, f),