Clean up old xauth entries

In a followup to a previous post on forwarding x sessions and su, here's a quick way to clean up old xauth entries.

> xauth list | cut -f1 -d\  | xargs -i xauth remove {}

You'll recall that cleanup will not happen automatically for the sessions that got su'ed to, so if you have several entries hanging around the one-liner will make quick work of them.