Changes
- Introduce desktop server administrators #872:
- The first user connected to the desktop session becomes a full administrator with full access to any locked windows and the ability to unconditionally shut down the server.
- When disconnected, administrators lose all privileges.
- Add user color indicators to the user list on the taskbar and draw a color focus mark next to the user cursor.
- Don't expose a window's Z-order state while it's inside a window manager. If you drag a window out of the window manager, it will immediately become on top if the AlwaysOnTop switch was set.
