Add an option to switch to external screen when closing the lid and on main power

Binary package hint: gnome-power-manager

gnome-power-manager configuration dialog should provide an option to just disable the laptop screen and enable the external one when closing the lid while AC powered.

It currently only offers a 'blank screen' option, which not only disable the laptop screen, but also the external one.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: gnome-power-manager 2.31.90-0ubuntu5
ProcVersionSignature: Ubuntu 2.6.35-19.28-generic 2.6.35.3
Uname: Linux 2.6.35-19-generic x86_64
Architecture: amd64
Date: Tue Aug 31 15:11:00 2010
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GnomeSessionSuspendInhibited: No
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Alpha amd64 (20100819)
MachineType: Dell Inc. Latitude E4300
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-19-generic root=UUID=a7fab861-76ed-4615-be73-119fe181d4af ro quiet splash
ProcEnviron:
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-power-manager
dmi.bios.date: 12/22/2009
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A14
dmi.board.name: 0D201R
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA14:bd12/22/2009:svnDellInc.:pnLatitudeE4300:pvr:rvnDellInc.:rn0D201R:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude E4300
dmi.sys.vendor: Dell Inc.