Provide UNR session for desktop

Work items:
Investigate on gconfd path regarding selected session and add it to gconf2 package: DONE
Add a /etc/gdm/custom.conf configuration file to GDM, needed to seed with a default configuration: DONE
Add new une-session.desktop file to ubuntu-netbook-remix-default-settings: DONE
Move gconfd setting path in ubuntu-netbook-remix-default-settings to comply with previous gconfd path work: DONE
Launch maximus and netbook launcher on UNE session only: DONE
Hide capplet panel choosing the window manager if mutter is running: DONE
Add gdmsetup setting to change the default session: DONE
Audit packages/modules related to runtime parts of the UNE session that may be impacted by installed packages: DONE
Check UNE installation on desktop doesn't mess up ubuntu-desktop experience: DONE
Detect 3D acceleration not available and end with a dialog telling you so: DONE

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status

pitti, 2009-11-30:
 * Please remove the UDS notes below, if/once they are completely integrated into the spec.
 * gconf path: Parsing Xsession.d/* for environment variables doesn't sound efficient, robust, and even if it would work. Can't desktop-une instead install an additional tree like the already existing ones in /var/lib/gconf/ ? Alternatively, add it to gconf proper, so it will be inert when une is not installed.
 * Please settle for one package name (desktop-une-session vs. une-session)
 * Please add work items

dbarth, 2009-12-03:
 * the GL test should be triggered, as efficiently as possible, in one of the session setup scripts. We can also do it in netbook-launcher, but the window manager may already have given up by the time we're started. One trick may be to have a command line option in netbook-launcher, to just do the test, and then stop. The trick here is that the launcher would already be pre-loaded and the second invocation (in the session, this time for real) should be accelerated by this initial run
 * for the test plan, i think the key scenario is:
  - log into a desktop session, add a funky applet on the panel
  - log into the UNE session, check that 'Applications, Places, etc.' are *not* displayed, the proper applets are loaded, and funky applet is not
  - log back into the desktop session and check that 'Applications, Places, etc.' *are* correctly displayed, and funky applet *is* too

JamieBennett, 2010-01-08:
* As part of https://blueprints.launchpad.net/ubuntu/+spec/mobile-lucid-une-2d-launcher the mobile team need to launch a specific instance of netbook-launcher(-efl) depending on the availability of 3D acceleration on our ARM based platforms. We require that after the availability of acceleration is determined, either the 3D Clutter based netbook-launcher is used or the 2D netbook-launcher-efl is used if no hardware is available.

It was discussed that a possible check for 3D acceleration could be to execute glxinfo | grep 'renderer string'.