3.10 "Display" Settings - Disable monitor not possible anymore - regression?

[Michael Flaig]

Hi folks,

I'm using UbuntuGNOME 13.10 with 3.10 (team, next, staging) and
xorg-edgers ppa.

I noticed that the new Displays settings have landed. But I think there
is a small regression there. I can't find a way to disable the internal
display. This was possible with 3.8 Display settings. 

When docked I use the main monitor only and had a setting for Gnome
which disables the internal display of my notebook leaving only the
external monitor active. The graphics card is not powerful enough in my
thinkpad T61 to drive both with acceptable performance.

Did I miss something? If not, should I open a bug with upstream for this
regression? 

Thanks,

Michael