def option_search( option, options )
      # Search in global options list
      options.each_value do |opt|
        return opt.longname.to_sym if option_compare( option, opt )
      end
      return nil
    end
def option_search( option, options )
      # Search in global options list
      options.each_value do |opt|
        return opt.longname.to_sym if option_compare( option, opt )
      end
      return nil
    end
Search option in application options.
 Return option key-name if option found, else return nil.
 option  -- object formed by getopt.
 options -- options object list.