ClearCase: Handle read-only view private files

View private files have state NotManaged. In the corner case
where a NotManaged file is read-only they should be made
writeable by the ReadOnlyFilesDialog, and not vcsOpen()-ed.

Change-Id: Icfeab6bebb76cc01da693b3bfff7b46c45b106b4
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/coreplugin/iversioncontrol.h

@@ -100,9 +100,9 @@ public:
     virtual bool supportsOperation(Operation operation) const = 0;
 
     /*!
-     * Returns the open support mode.
+     * Returns the open support mode for \a fileName.
      */
-    virtual OpenSupportMode openSupportMode() const;
+    virtual OpenSupportMode openSupportMode(const QString &fileName) const;
 
     /*!
      * Called prior to save, if the file is read only. Should be implemented if