Display MCS plugin

[Olivier Fourdan]

Hi Pasi,

Pasi Orovuo wrote:
> A while back I discussed in irc with Jasper about the problems with the
> display mcs plugin. Among requiring a "dummy default" value, we found
> that the behaviour of the Revert button isn't the most expected, as it
> just restored the gamma sliders to their defaults.
> 
> Based on our discussion I made an attempt[1] to address the issues.
> Basically the changes are:
> 
>  1) The "Default" option that, if selected, does nothing on startup.
>  2) The revert button, which now reverts the values to those selected
>     prior showing the display preferences dialog (which appeared as
>     the correct behaviour to me)
>  3) Resolution change confirmation. This wasn't something we agreed upon
>     with Jasper, but rather something I already had written[2] and
>     decided to leave there. Can and will be removed if it's found
>     inappropriate (it's also the reason for Gtk+ 2.6 requirement).
> 
> For me it seems to work, but I cannot reproduce the problems people are
> having in a few bugzilla entries. I understood Jasper had a way of
> testing them, so I decided to "publish" the patch here for him (and
> everyone interested) to test.

Works for me, highly needed, so it's committed.

Thanks a lot for contributing this.

Cheers,
Olivier.