Provide correct links to download the Mac OS X distribution depending on product.
Update the portable (usb stick) installation instructions for Linux.
Fix issue 53 - remove the topics that describe how to run oXygen from an usb stick.
Merge branch 'dev'

* dev:
  Fix issue 53 - remove the topics that describe how to run oXygen from an usb stick.
  Update the portable (usb stick) installation instructions for Linux.
  Provide correct links to download the Mac OS X distribution depending on product.