[cairo] nquartz surface renamed to quartz

[Vladimir Vukicevic]

Hi all,

I've replaced the old quartz surface with nquartz (with appropriate 
renaming) in preparation for 1.4.  The Quartz surface will still remain 
experimental, because it needs much more widespread testing and because 
of a few remaining known bugs.

The known issues:
    - lines are not scaled as they are with cairo's image backend; see 
bug 10036.  Brian's patch in there is probably the right way to go, 
though it might make sense to only do that if it's necessary.
    - all image patterns are drawn as EXTEND_REPEAT; this will be most 
obvious if you use an EXTEND_NONE image pattern and then call paint() 
without a clip set to the bounds of the image.  I'm going to try to fix 
this soon.

Please report any other issues that come up!

    - Vlad