Bring back the remembering feature of the expanded/collapsed status of the tools. See issue 2648. Additionnally, correct a GUI bug of the B&W tool: the display wasn't initialized correctly when opening a new editor.

rtgui/filepanel.cc

@@ -139,6 +139,12 @@ FilePanel::~FilePanel () {
         delete inspectorPanel;
 }
 
+void FilePanel::on_realize () {
+    Gtk::HPaned::on_realize ();
+    tpc->closeAllTools();
+}
+
+
 void FilePanel::setAspect () {
 	int winW, winH;
 	parent->get_size(winW, winH);