Restoring the Lock Screen menu item

[Corey Burger]

Hello all,

Late in the dapper cycle we removed the lock screen menu item. I think
we should restore it, for the following reasons:

1. It is used many times a day, as whereas the rest of the items on
the logout dialog are rarely used more than once per day
2. Using the logout dialog is slow. You need to wait the extra 1-2
secs for the dialog to pop
3. The system menu is not cluttered

Please, lets keep this on topic and not devolve into a discussion of
the rest of the logout dialog.

Corey