Port tone equalizer from ART

Merge with local adjustments tone equalizer image processing function
for consistent results.

To-do: Enable for batch editing and add pivot/colormap to the local
adjustments version.

rtgui/toneequalizer.h

@@ -0,0 +1,56 @@
+/* -*- C++ -*-
+ *
+ *  Adapted from ART.
+ *
+ *  This file is part of RawTherapee.
+ *
+ *  Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
+ *
+ *  RawTherapee is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  RawTherapee is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <gtkmm.h>
+#include "adjuster.h"
+#include "toolpanel.h"
+
+class ToneEqualizer: public ToolParamBlock, public AdjusterListener, public FoldableToolPanel {
+public:
+    ToneEqualizer();
+
+    void read(const rtengine::procparams::ProcParams *pp, const ParamsEdited* pedited = nullptr) override;
+    void write(rtengine::procparams::ProcParams *pp, ParamsEdited* pedited = nullptr) override;
+    void setDefaults(const rtengine::procparams::ProcParams *defParams, const ParamsEdited* pedited = nullptr) override;
+    void adjusterChanged(Adjuster *a, double newval) override;
+    void adjusterAutoToggled(Adjuster *a) override;
+    void enabledChanged() override;
+
+    void trimValues(rtengine::procparams::ProcParams *pp) override;
+
+private:
+    void colormapToggled();
+
+    std::array<Adjuster *, 5> bands;
+    Adjuster *regularization;
+    Adjuster *pivot;
+    Gtk::CheckButton *show_colormap;
+
+    rtengine::ProcEvent EvEnabled;
+    rtengine::ProcEvent EvBands;
+    rtengine::ProcEvent EvRegularization;
+    rtengine::ProcEvent EvColormap;
+    rtengine::ProcEvent EvPivot;
+
+    rtengine::procparams::ToneEqualizerParams inital_params;
+};