session-quit: Use a unique dialog server address for each session.
This was preventing the logout dialog for subsequent users logged
in, as it would attempt to connect to the original user's server
(and be denied).
- A unique address will be generated at startup, and passed to
the dialog when it is launched.
- Log output from the c-s-owned dialog process when debugging is
enabled.
This causes the dialog to be centered when launched.
Currently, muffin treats any decorated window as 'normal' unless
it's marked modal, regardless of its window hint (normal, dialog,
modal-dialog). Normal windows are subject to normal window
placement rules.
