Adding new units for the RGB and HSV values in the Navigator tool (below

Histogram). Click on one of thes two columns to cycle to a new unit
independantly, between [0-1], [0-255], [%]  (Hue stays in degree instead
of percent). The current unit is saved in Options for new Editor tabs or
between sessions.

rtgui/navigator.h

@@ -22,6 +22,7 @@
 #include <gtkmm.h>
 #include "previewwindow.h"
 #include "pointermotionlistener.h"
+#include "options.h"
 #include "../rtengine/iccstore.h"
 
 class Navigator : public Gtk::Frame, public PointerMotionListener
@@ -29,6 +30,12 @@ class Navigator : public Gtk::Frame, public PointerMotionListener
 
     typedef const double (*TMatrix)[3];
 
+private:
+    Options::NavigatorUnit currentRGBUnit;
+    Options::NavigatorUnit currentHSVUnit;
+    void cycleUnitsRGB (GdkEventButton *event);
+    void cycleUnitsHSV (GdkEventButton *event);
+
 protected:
     Gtk::Label* position;
     Gtk::Label *R, *G, *B;