added haze removal tool

Based on the paper:
  "Single Image Haze Removal Using Dark Channel Prior" by He, Sun and Tang
using a guided filter for the "soft matting" of the transmission map

rtgui/paramsedited.h

@@ -724,6 +724,14 @@ public:
     bool strength;
 };
 
+class DehazeParamsEdited
+{
+public:
+    bool enabled;
+    bool strength;
+};
+
+
 class RAWParamsEdited
 {
 
@@ -865,6 +873,7 @@ public:
     HSVEqualizerParamsEdited      hsvequalizer;
     FilmSimulationParamsEdited    filmSimulation;
     SoftLightParamsEdited         softlight;
+    DehazeParamsEdited            dehaze;
     MetaDataParamsEdited          metadata;
     bool                          exif;
     bool                          iptc;