pkg-config: upgrade to 0.29.2 and build with internal glib

Building normal glib is a nightmare, at least as long as we
haven't stopped using Python 2, so let's try to avoid it.

This makes bin/pkg-config bigger (GCC 6.3.0):
 old size:  47880
 new size: 573992

With Link Time Optimization, GCC 8.3.0 produces a binary of 154656 bytes.
However, GCC 6.3.0 fails to link so we have to wait.

component/pkgconfig/buildout.cfg

@@ -4,30 +4,12 @@
 [buildout]
 parts =
   pkgconfig
-extends =
-  ../gettext/buildout.cfg
-  ../glib/buildout.cfg
-
-[pkg-config]
-<= pkgconfig
 
 [pkgconfig]
 recipe = slapos.recipe.cmmi
 shared = true
-url = https://pkgconfig.freedesktop.org/releases/pkg-config-0.29.tar.gz
-md5sum = 77f27dce7ef88d0634d0d6f90e03a77f
-location = @@LOCATION@@
-# build pkg-config twice so that second configure can use pkg-config
-# to compute GLIB_CFLAGS and GLIB_LIBS.
-pre-configure =
-  ./configure --prefix=${:location} --with-installed-glib && make
+url = https://pkgconfig.freedesktop.org/releases/pkg-config-0.29.2.tar.gz
+md5sum = f6e931e319531b736fadc017f470e68a
 configure-options =
-  --with-installed-glib
+  --with-internal-glib
   --disable-host-tool
-environment =
-  PATH=.:%(PATH)s
-  PKG_CONFIG_PATH=${glib:location}/lib/pkgconfig:${pcre:location}/lib/pkgconfig
-  CPPFLAGS=-I${glib:location}/include
-  LDFLAGS=-L${gettext:location}/lib -Wl,-rpath=${gettext:location}/lib -L${glib:location}/lib -Wl,-rpath=${glib:location}/lib
-  GLIB_CFLAGS=-I${glib:location}/include/glib-2.0 -I${glib:location}/lib/glib-2.0/include
-  GLIB_LIBS=-L${glib:location}/lib -lglib-2.0 -lintl