metadata: initialize thumbnail rating from exif

(cherry picked from commit 96bd2db0d2e127678bded3bee7aa3275332826c0)

rtengine/imagedata.cc

@@ -287,6 +287,10 @@ FramesData::FramesData(const Glib::ustring &fname) :
             expcomp = pos->toFloat();
         }
 
+        if (find_exif_tag("Exif.Image.Rating")) {
+            rating = pos->toLong();
+        }
+
         // -----------------------
         // Special file type detection (HDR, PixelShift)
         // ------------------------
@@ -567,12 +571,6 @@ std::string FramesData::getOrientation() const
 }
 
 
-int FramesData::getRating() const
-{
-    return rating;
-}
-
-
 void FramesData::setDCRawFrameCount(unsigned int frameCount)
 {
     dcrawFrameCount = frameCount;
@@ -589,6 +587,12 @@ Glib::ustring FramesData::getFileName() const
     return fname_;
 }
 
+
+int FramesData::getRating() const
+{
+    return rating;
+}
+
 //------inherited functions--------------//
 
 std::string FramesMetaData::apertureToString(double aperture)

rtengine/imagedata.h

@@ -81,8 +81,8 @@ public:
     std::string getLens() const override;
     std::string getSerialNumber() const;
     std::string getOrientation() const override;
-    int getRating() const override;
     Glib::ustring getFileName() const override;
+    int getRating() const override;
 };
 
 }

rtengine/rtengine.h

@@ -1,4 +1,5 @@
-/*
+/* -*- C++ -*-
+ *  
  *  This file is part of RawTherapee.
  *
  *  Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>