Fix exports on DeepImageChannel and FlatImageChannel.

If the whole class isn't exported, the typeinfo doesn't get exported,
and so dynamic casting into those classes will not work.

Note that this is a manual port of bb3bb3f from the RB-3.1 branch.
I was unable to do a cherry-pick due to conflicts from minor text
formatting differences between branches.

src/lib/OpenEXRUtil/ImfDeepImageChannel.h

@@ -41,7 +41,7 @@ class SampleCountChannel;
 // of the level.
 //
 
-class IMFUTIL_EXPORT_TYPE DeepImageChannel : public ImageChannel
+class IMFUTIL_EXPORT DeepImageChannel : public ImageChannel
 {
 public:
     //
@@ -56,21 +56,21 @@ class IMFUTIL_EXPORT_TYPE DeepImageChannel : public ImageChannel
     // Access to the image level to which this channel belongs.
     //
 
-    IMFUTIL_EXPORT DeepImageLevel&       deepLevel ();
-    IMFUTIL_EXPORT const DeepImageLevel& deepLevel () const;
+    DeepImageLevel&       deepLevel ();
+    const DeepImageLevel& deepLevel () const;
 
     //
     // Access to the sample count channel for this deep channel.
     //
 
-    IMFUTIL_EXPORT SampleCountChannel&       sampleCounts ();
-    IMFUTIL_EXPORT const SampleCountChannel& sampleCounts () const;
+    SampleCountChannel&       sampleCounts ();
+    const SampleCountChannel& sampleCounts () const;
 
 protected:
     friend class DeepImageLevel;
 
-    IMFUTIL_EXPORT DeepImageChannel (DeepImageLevel& level, bool pLinear);
-    IMFUTIL_EXPORT virtual ~DeepImageChannel ();
+    DeepImageChannel (DeepImageLevel& level, bool pLinear);
+    virtual ~DeepImageChannel ();
 
     DeepImageChannel (const DeepImageChannel& other) = delete;
     DeepImageChannel& operator= (const DeepImageChannel& other) = delete;
@@ -93,7 +93,7 @@ class IMFUTIL_EXPORT_TYPE DeepImageChannel : public ImageChannel
 
     virtual void initializeSampleLists () = 0;
 
-    IMFUTIL_EXPORT virtual void resize ();
+    virtual void resize ();
 
     virtual void resetBasePointer () = 0;
 };

src/lib/OpenEXRUtil/ImfFlatImageChannel.h

@@ -38,7 +38,7 @@ class FlatImageLevel;
 // only for pixels within the data window of the level.
 //
 
-class IMFUTIL_EXPORT_TYPE FlatImageChannel : public ImageChannel
+class IMFUTIL_EXPORT FlatImageChannel : public ImageChannel
 {
 public:
     //
@@ -53,24 +53,22 @@ class IMFUTIL_EXPORT_TYPE FlatImageChannel : public ImageChannel
     // Access to the flat image level to which this channel belongs.
     //
 
-    IMFUTIL_EXPORT FlatImageLevel&       flatLevel ();
-    IMFUTIL_EXPORT const FlatImageLevel& flatLevel () const;
+    FlatImageLevel&       flatLevel ();
+    const FlatImageLevel& flatLevel () const;
 
 protected:
     friend class FlatImageLevel;
 
-    IMFUTIL_EXPORT
     FlatImageChannel (
         FlatImageLevel& level, int xSampling, int ySampling, bool pLinear);
 
-    IMFUTIL_EXPORT virtual ~FlatImageChannel ();
+    virtual ~FlatImageChannel ();
 
     FlatImageChannel (const FlatImageChannel& other) = delete;
     FlatImageChannel& operator= (const FlatImageChannel& other) = delete;
     FlatImageChannel (FlatImageChannel&& other)                 = delete;
     FlatImageChannel& operator= (FlatImageChannel&& other) = delete;
 
-    IMFUTIL_EXPORT
     virtual void resize ();
 
     virtual void resetBasePointer () = 0;