[Xcb] XListFontsWithInfo works, finally!

[Jamey Sharp]

Hey all,

I couldn't sleep, so in a sleepless haze I figured out the details of
how XCB should handle multiple replies, as in ListFontsWithInfo and
RECORD requests. I even got memory management just right, I think. Of
course, as promised, much of XCB's run-time error checking is gone now;
we'll have to figure out how to put it back later.

Together with a single-character bugfix to Xlib, XListFontsWithInfo
"just works" now. I've gone through the five stages of grief over this
stupid request, I swear.

If somebody wanted to add ListFontsWithInfo to xcb-proto/src/xproto.xml,
we'd be all set. Obviously people can also start playing with the RECORD
extension again now.

Unfortunately, it looks like there's some regression on the X Test
Suite: several tests hang, for reasons I haven't tracked down yet. But
at least there aren't any assertion failures for XListFontsWithInfo any
more. (*does a happy dance*) And as Firefox and xterm seem fine, I not
only can't see evidence that the test suite is finding real errors, but
I don't particularly care since everything I use works. ;-)

With that bit of code out of my head, maybe I can get some sleep now.

--Jamey