Change logout message to be more user friendly

Currently if someone is logged out, they get a page with the following text:

Automated Logout

You have been logged out by the Automated Logout Module.

I think it is good to have a message, but a user has no idea what an "Automated Logout Module" is and shouldn't need to know. I would prefer something like the following which doesn't mention the module and would be more familiar:

Logged out

You have been automatically logged out due to inactivity.