If it is even planned for anyone outside to access it; when I try to download it asks for authentification
Right click on the folder where you want to create the local repository folder (suggest your mod folder), choose SVN Checkout. You'll be prompted for the repository URL and the name of the folder where you'll make your mirror. Then sit back and wait while the SVN client pulls all the files.
To update your mirror, choose SVN Update from the right click menu.
2.2.0.4 is what SVN is patched to.
You should use https://lux-invicta-repository.googlecode.com/svn/trunk/ for checkout, the other is to go to the SVN website.