Add Alpha RGB GLX Visuals to xorg.conf for nVidia cards

Unfortunately there is no debconf setting to add additional options, so whenever we call dexconf, the settings get lost. The clean solution would be to add proper video driver option support to the xorg source package's dexconf program.

 xorg (1:7.2-0ubuntu6) feisty; urgency=low
 .
   * xserver-xorg.templates: Add xserver-xorg/config/device/extra_options so
     that extra graphics driver options can be set through debconf and
     respected by dexconf. We need this in restricted-manager to make
     restricted drivers like nvidia work OOTB for compiz, but it is certainly
     useful for other things, too. (NB that the question is never asked
     interactively).
   * debian/local/dexconf: Read above debconf key, parse it (first token is
     option name, rest of the line after first space is value), and add it as
     Option lines to the device section. (LP: #90109)

Fixed in bzr head.

 restricted-manager (0.3) feisty; urgency=low
 .
   * RestrictedManager/core.py: Add DefaultHandler classmethods
     package_installed(), install_package(), and remove_packagage().
   * RestrictedManager/nvidia.py: Install/Remove the nvidia-glx{,-legacy}
     package when enabling/disabling one of the Nvidia drivers. (LP: #90205)
   * RestrictedManager/nvidia.py: Enable AddARGBGLXVisuals option when using
     the non-legacy driver, so that compiz works out of the box. (LP: #90109)

xorg (1:7.2-3ubuntu1) gutsy; urgency=low

  * Merge from Debian unstable. Remaining changes:
    - debian/control, debian/scripts/vars.sparc, debian/rules:
      + Makes xorg Architecture: any and use an extra variable
        to not Depends on type-handling.
    - debian/control:
      + Keep meta-packages for xbase-clients, xutils.
      + Change the Maintainer-field.
      + Add replaces for xinit since we now ship Xsession from x11-common.
        Ditto for xrgb as we ship rgb.txt in x11-common.
      + xserver-xorg: Add dependancy "OR xserver-xorg-video" because
        the restricted drivers provide that.
    - debian/local/Xsession:
      + If ~/.xsession-errors is bigger than 0.5MiB, truncate it to the last
        0.5MiB to avoid having it grow indefinitively. (This does not happen
        with gdm anyway since gdm cleans the file on login). (LP #60448)
    - debian/local/dexconf:
      + Uncoditionally re-enable ZAxisMapping in dexconf. (LP: #31827)
      + Add InputDevice entries for wacom.
      + Add extra bits for ps3fb xorg.conf.
      + Read xserver-xorg/config/device/extra_options key, parse it
        (first token is option name, rest of the line after first space
        is value), and add it as Option lines to the device section.
        (LP: #90109)
      + Add special case for i810 with 3M TouchScreen monitors to set a
        resolution of 800x600 and avoid probing since it will fail miserably
        in xserver-xorg.postinst. Also make sure to write Option "DisplayInfo"
        "False" in Device Section in dexconf if the above combination is
        matched otherwise the card will display extra unrequired info each
        time X attempts a startup. (touches also xserver-xorg.postinst.in)
      + Due to a very annoying DRI/DRM bug, make sure to use OldDmaInit
        when writing down the Device section for mga driver. This will make
        DRI working at least for AGP cards. PCI didn't work before and it will
        keep not working since the option does explicitly disable DRI for PCI.
        (LP: #27442)
      + Enable elographics driver when matching known machines.
      + Disable composite when using the fglrx driver. It does not support
        composition, and enabling it by default (as recently done in
        xorg-server) breaks DRI for fglrx. (LP: #90688)
    - debian/scripts/vars.i386:
      + Add xserver-xorg-input-elographics to XSERVER_XORG_INPUT_DEPENDS.
    - debian/xserver-xorg.postinst.in:
      + Add lt to list of non-Latin keymaps (LP: #38931).
      + Make sure to ask video driver on sparc even if autodetected. Some
        cards still require weird overrides (ati -> fbdev) that are not
        100% known in all combinations.
      + Skip video card autodetection if xforcevesa is set
        (LP #27020, #59618).
      + Detect keyboard layout configuration using /etc/default/console-setup
        if available.
      + Clean up duplicate keymaps in xserver-xorg.config.in and make sure
        they're all neatly alphabetised.
      + Map cf console keymap to ca(fr).
      + Map croat console keymap to hr. (LP: #43598)
      + Set default keyboard variant for French to oss (LP: #89835).
      + Map...

A distribution upgrade From 7.04 to 7.10b did not fix this bug.

Still had to implement fix manually in xorg.conf. Just FYI.

I also suspect displayconfig-gtk strips out ARGBGLXVisuals.