[rekonq] Enable the raster graphic system by default on X11

[benjamin.poulain at nokia.com]

> Hello, i'm currently using it with qt 4.7 beta2 but there are some bugs with
> fonts color management... (see screenshots).
> 
> http://adishatz.1s.fr/~gnumdk/kmail_classic.png
> http://adishatz.1s.fr/~gnumdk/kmail_raster.png

Do you have a bug opened for this on http://bugreports.qt.nokia.com/?

> After some more testing, i've got others bugs:
> http://bugreports.qt.nokia.com/browse/QTBUG-12238

Rejected as invalid :-)

> Raster engine isn't really tested, distributions don't want to enable it by
> default, i think a good solution should be to be able to enable it in qtconfig
> if you want more users to test it.

It is the default engine on Windows, I would say it is rather well tested in that respect :)
We also use it internally in favor of X11.

In the development of QtWebKit, we target mainly raster, with some layers being rendered through OpenGL when possible. For me, it would only make sense to follow this also in Rekonq.

cheers,
Benjamin