pango and cairo pc

["Mike Emmel" <mike emmel gmail com>]

Hi all I recently change the configure.in for gtk to check for cairo-directfb.pc

I was looking at the pango configure.in and am wondering if it might
need to also check for
backend specific pc files.  I don't think so but would like to know
what others think.

It does test for the xlib backend with a program for example should
that just try for the xlib pc file ?

Mike