KLinkItemSelectionModel: Add new default constructor.

Make it possible to construct this in QML

src/klinkitemselectionmodel.cpp

@@ -94,6 +94,12 @@ KLinkItemSelectionModel::KLinkItemSelectionModel(QAbstractItemModel *model, QIte
     setLinkedItemSelectionModel(proxySelector);
 }
 
+KLinkItemSelectionModel::KLinkItemSelectionModel(QObject *parent)
+    : QItemSelectionModel(Q_NULLPTR, parent),
+      d_ptr(new KLinkItemSelectionModelPrivate(this))
+{
+}
+
 KLinkItemSelectionModel::~KLinkItemSelectionModel()
 {
     delete d_ptr;

src/klinkitemselectionmodel.h

@@ -104,6 +104,9 @@ public:
       Constructor.
     */
     KLinkItemSelectionModel(QAbstractItemModel *targetModel, QItemSelectionModel *linkedItemSelectionModel, QObject *parent = 0);
+
+    explicit KLinkItemSelectionModel(QObject *parent = Q_NULLPTR);
+
     ~KLinkItemSelectionModel();
 
     QItemSelectionModel *linkedItemSelectionModel() const;