====== creating .dmg for install with background ======
  - make a new folder (for this example: AppBundle)
  - drag the finished application file (.app) and any other files you want the user to have into AppBundle
  - create a background image (png file)
  - using the terminal, create a hidden directory named .background in AppBundle
  - copy the background image into the .background folder
  - open Disk Utility
  - drag the AppBundle folder onto the Disk Utility icon, or use File -> New -> Disk Image from Folder... and select AppBundle
  - set the Image Format to read/write, and don't use encryption
  - save the dmg file as "AppBundle read-write.dmg"
  - mount (open) the "AppBundle read-write.dmg" file in the Finder
  - press command-j to bring up the window settings dialog
  - click "This window only" so the changes won't modify any other folders
  - in the Background section, select Picture
  - since the image is in a hidden folder, use command-shift-g to bring up the Go To Folder sheet
  - type the full page to the background folder: /Volumes/AppBundle/.background and click Go
  - select the background image, and click Select (Finder needs to have "show all file extensions" enabled)
  - adjust the icons and window as desired:
    * icon size
    * text size and label position
    * show or hide sidebar and toobar
    * window size
    * window position
  - once you have the window looking exactly the way you want users to see it, unmount the dmg file (eject)
  - in Disk Utility, use the convert tool on the AppBundle read-write.dmg file
    * set the Image Format to "compressed"
    * save the file as AppBundle.dmg
  - AppBundle.dmg should open up with your view settings intact