added a more flexible way of managing ProcEvents

modifying the global ProcEvent enum and refreshmap array is not needed
anymore. You can now register new events dynamically, using a ProcEventMapper
instance. See rtgui/localcontrast.cc for an example.

Hopefully this solves the problem of recurring merge conflicts when different
devs add different proc events

rtgui/eventmapper.h

@@ -0,0 +1,37 @@
+/* -*- C++ -*-
+ *  
+ *  This file is part of RawTherapee.
+ *
+ *  Copyright (c) 2017 Alberto Griggio <alberto.griggio@gmail.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 <string>
+#include <unordered_map>
+#include "../rtengine/refreshmap.h"
+
+
+class ProcEventMapper {
+public:
+    static ProcEventMapper *getInstance();
+    rtengine::ProcEvent newEvent(int action, const std::string &history_msg="");
+    const std::string &getHistoryMsg(rtengine::ProcEvent event) const;
+
+private:
+    ProcEventMapper();
+    
+    std::unordered_map<int, std::string> history_msgs_;
+};