pkg-config

[Havoc Pennington <hp redhat com>]

Hi,

In making the changes to clean up .pc files to have files specific to
the various GDK targets, it turns out that it's convenient to go ahead
and use pkg-config to detect Pango. So this will make GTK depend on
pkg-config for building.

Any objections to the following changes:
 - remove glib-config-2.0, pango-config, gtk-config-2.0
 - adjust m4 macros to use pkg-config
 - use pkg-config in configure.in scripts for Pango and GTK

?

pkg-config is available for download from pkgconfig.sourceforge.net.

The reason to do this is that it's going to be error prone to keep the
various -config scripts in sync with the .pc files, and the whole
point of pkg-config is to obsolete the -config scripts and m4 macros.
We should go ahead and make the change now, rather than waiting until
just before release.

I'll make the change if there are no objections.

Havoc