[cairo] GSoC/scan converting rasteriser update

[M Joonas Pihlaja]

Hulo cairo-l,

I've pushed my pending updates to the blog at

http://people.freedesktop.org/~joonas/status-blog/

The short of it is that after diving into the surface-fallback
code I realised that I didn't *really* understand the compositing
model after all -- especially when it comes to clipping and
masking.  I've added a proposed update to the documentation as a
post.  I'd be much obliged if someone could give it a glance
over.

Also, last week I actually didn't do much as per schedule (guess
I should've updated the blog at least...)

Cheers,

Joonas