RecentResourceListModel: added item(QModelIndex) method

Added an item(QModelIndex) method to RecentResourceListModel which
maps given QModelIndex to source model and returns the according
ResourceItem from the source model.

include/RecentResourceListModel.h

@@ -50,6 +50,8 @@ public:
 		return m_model;
 	}
 
+	ResourceItem * item( const QModelIndex & _idx );
+
 
 protected:
 	// compares items at two indices by date-property