GHS: Update project layout to build targets correctly

-- Restructure projects and files to support proper building of targets
   Build order is determined by hierarchy of project files and folders
   Custom targets may have been run multiple times in the original file / folder structure
-- Default to build targets that are part of ALL target
-- List all known targets for this project
   Includes global targets for ALL_BUILD and INSTALL
-- Compute build order for building targets

Source/cmGhsMultiTargetGenerator.h

@@ -66,7 +66,7 @@ private:
   void WriteSourceProperty(std::ostream& fout, const cmSourceFile* sf,
                            std::string const& propName,
                            std::string const& propFlag);
-  void WriteReferences(std::ostream& fout);
+  void WriteReferenceFile(std::string fproj);
   static void WriteObjectLangOverride(std::ostream& fout,
                                       const cmSourceFile* sourceFile);