def output path, do_file_close = true
      FileUtils.cp @file.path, path
      close if do_file_close
      self
    end
def output path, do_file_close = true
      FileUtils.cp @file.path, path
      close if do_file_close
      self
    end
Creates a new instance of AviGlitch::Base, open the file and
 make it ready to manipulate.
 It requires +path+ as Pathname.

 Outputs the glitched file to +path+, and close the file.