documentation and folded item delegates from old code back in

app/widget/projectexplorer/projectexplorernavigation.h

@@ -0,0 +1,16 @@
+#ifndef PROJECTEXPLORERLISTVIEWTOOLBAR_H
+#define PROJECTEXPLORERLISTVIEWTOOLBAR_H
+
+#include <QPushButton>
+#include <QWidget>
+
+class ProjectExplorerNavigation : public QWidget
+{
+public:
+  ProjectExplorerNavigation(QWidget* parent);
+
+private:
+  QPushButton* dir_up_btn_;
+};
+
+#endif // PROJECTEXPLORERLISTVIEWTOOLBAR_H