These are the changes:
* Win/OS X/Linux: The borders that prevent you to enter areas outside the chapter boundaries now works correctly.
* OS X: The game is now code signed.
* OS X/Linux: Portable Mode (which makes the game store settings in its own application folder) is now disabled by default. You can enable it in Game.ini
* OS X/Linux: A bug was fixed with the game storing savegames in the incorrect path if portable mode was disabled.
If everything works for you, there's no need to get this update. No secrets are added.