Comment 2 for bug 1291748

In Xubuntu we decided to go for an easy solution, we ship a desktop-file for light-locker that is empty, hence disabling it.

(You can obviously also ship a desktop-file with a different startup-command if you want to give ppl a way to lock their live-session and only disable timed locking)

For reference, see this bugreport and this commit, which implements our solution:
https://bugs.launchpad.net/ubuntu/+source/light-locker/+bug/1281323
http://bazaar.launchpad.net/~smd-seandavis/xubuntu-default-settings/light-locker-live/revision/459