code: public void copyDirectory(ModuleElement mdle, DocPath dir) throws DocFileIOException  {
          copyDirectory(getLocationForModule(mdle), dir);
      }
docs: Copy the given directory and its contents from the source
  module directory to the generated documentation directory.
  For example, given a package java.lang, this method will
  copy the entire directory, to the generated documentation
  hierarchy.
  
  @param mdle the module containing the directory to be copied
  @param dir the directory to be copied
  @throws DocFileIOException if there is a problem while copying
  the documentation files