Add RAII listener blocking utility

* Added for ToolPanel listener and Adjuster
* Follows style of ConnectionBlocker for sigc::connection

rtgui/guiutils.h

@@ -45,7 +45,9 @@ struct CropParams;
 
 }
 
+class Adjuster;
 class RTImage;
+class ToolPanel;
 
 Glib::ustring escapeHtmlChars(const Glib::ustring &src);
 bool removeIfThere (Gtk::Container* cont, Gtk::Widget* w, bool increference = true);
@@ -161,6 +163,26 @@ private:
     bool wasBlocked;
 };
 
+class BlockAdjusterEvents
+{
+public:
+    explicit BlockAdjusterEvents(Adjuster* adjuster);
+    ~BlockAdjusterEvents();
+
+private:
+    Adjuster* adj;
+};
+
+class DisableListener
+{
+public:
+    explicit DisableListener(ToolPanel* panelToDisable);
+    ~DisableListener();
+
+private:
+    ToolPanel* panel;
+};
+
 /**
  * @brief Glue box to control visibility of the MyExpender's content ; also handle the frame around it
  */