Replace every use of the foreach macro with a C++11 range-based for loop

This prevents a race condition with Qt5. A foreach loop makes a copy of its
Qt container, increasing the reference count to the container's internal
data. Qt5 often asserts isDetached(), which requires the reference count to
be <= 1. This assertion fails when the foreach loop increases the reference
count at exactly the wrong moment. Using a range-based for loop prevents an
unnecessary copy from being made and ensures this race condition isn't
triggered.

src/gui/EffectSelectDialog.cpp

@@ -216,7 +216,7 @@ void EffectSelectDialog::rowChanged( const QModelIndex & _idx,
             subLayout->setSpacing( 0 );
             m_currentSelection.desc->subPluginFeatures->
                 fillDescriptionWidget( subWidget, &m_currentSelection );
-            foreach( QWidget * w, subWidget->findChildren<QWidget *>() )
+            for( QWidget * w : subWidget->findChildren<QWidget *>() )
             {
                 if( w->parent() == subWidget )
                 {