Restore ACL support

[PierreBesson]

ACL support was removed a long time ago waiting for a spring bug to be fixed. I believe it is now fixed so we should activate ACLs again.
However I have no time or motivation to do this at the moment. If anyone want to give it a shot.

[xetys]

I tried that some time ago, but there is still something broken, and I only had few time to dig for the issue. I can check it out