Remove unneeded IEditorFactor::open re-implementations.

Change-Id: I261bc1ee09a2c22155e4874a4429a868d837c256
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: David Schulz <david.schulz@digia.com>

src/plugins/imageviewer/imageviewerfactory.h

@@ -50,7 +50,6 @@ public:
     QStringList mimeTypes() const;
     Core::Id id() const;
     QString displayName() const;
-    Core::IDocument *open(const QString &fileName);
 
     void extensionsInitialized();