title: make mac package/bundle programmatically
body: <p>through terminal you can make it with a command - "SetFile -a B filename"</p>
  
  <p>programmatically i think i should set one of the attributes through 
  [[NSFileManager defaultManager] createDirectoryAtPath:dirPath withIntermediateDirectories:NO attributes:attributes error:nil];</p>
  
  <p>but i can't find which one.</p>
  
  <p>thanks</p>