fix -Wextra in FreeCADGui

src/Gui/iisTaskPanel/src/iisiconlabel.cpp

@@ -83,6 +83,7 @@ QSize iisIconLabel::minimumSizeHint() const
 
 void iisIconLabel::paintEvent ( QPaintEvent * event ) 
 {
+	Q_UNUSED(event); 
 	QPainter p(this);
 
 	QRect textRect(rect().adjusted(0,0,-1,0));

src/Gui/iisTaskPanel/src/iistaskbox.cpp

@@ -150,6 +150,7 @@ void iisTaskBox::processShow()
 
 void iisTaskBox::paintEvent ( QPaintEvent * event ) 
 {
+	Q_UNUSED(event); 
 	QPainter p(this);
 
 	if (myDummy->isVisible()) {

src/Gui/iisTaskPanel/src/iistaskgroup.cpp

@@ -50,6 +50,7 @@ void iisTaskGroup::addIconLabel(iisIconLabel *label, bool addToLayout)
 
 void iisTaskGroup::paintEvent ( QPaintEvent * event ) 
 {
+	Q_UNUSED(event); 
 	QPainter p(this);
 
 	//p.setOpacity(/*m_opacity+*/0.7);

src/Gui/iisTaskPanel/src/iistaskheader.cpp

@@ -97,6 +97,7 @@ void iisTaskHeader::setScheme(iisTaskPanelScheme *scheme)
 
 void iisTaskHeader::paintEvent ( QPaintEvent * event ) 
 {
+	Q_UNUSED(event); 
 	QPainter p(this);
 
 #if QT_VERSION >= 0x040203

src/Gui/iisTaskPanel/src/iistaskpanel.cpp

@@ -52,6 +52,7 @@ void iisTaskPanel::setScheme(iisTaskPanelScheme *scheme)
 
 void iisTaskPanel::paintEvent ( QPaintEvent * event ) 
 {
+	Q_UNUSED(event); 
 	QPainter p(this);
 
 	//p.setOpacity(0.5);
@@ -72,6 +73,7 @@ void iisTaskPanel::removeWidget(QWidget *w)
 
 void iisTaskPanel::addStretch(int s)
 {
+	Q_UNUSED(s); 
 	if (!mySpacer) {
 		mySpacer = new QSpacerItem(0,0,QSizePolicy::Minimum, QSizePolicy::Expanding);
 		layout()->addItem(mySpacer);