gnu: Move numerous "inputs" which should be "native-inputs".

* gnu/packages/avahi.scm, gnu/packages/cdrom.scm, gnu/packages/cryptsetup.scm,
  gnu/packages/curl.scm, gnu/packages/emacs.scm, gnu/packages/fontutils.scm,
  gnu/packages/gdb.scm, gnu/packages/geeqie.scm, gnu/packages/ghostscript.scm,
  gnu/packages/glib.scm, gnu/packages/gnome.scm, gnu/packages/gnunet.scm,
  gnu/packages/gnupg.scm, gnu/packages/gnuzilla.scm, gnu/packages/graphviz.scm,
  gnu/packages/groff.scm, gnu/packages/gstreamer.scm, gnu/packages/gtk.scm,
  gnu/packages/gv.scm, gnu/packages/imagemagick.scm, gnu/packages/irssi.scm,
  gnu/packages/kde.scm, gnu/packages/libcanberra.scm, gnu/packages/libtiff.scm,
  gnu/packages/linux.scm, gnu/packages/lvm.scm, gnu/packages/mp3.scm,
  gnu/packages/netpbm.scm, gnu/packages/parted.scm, gnu/packages/pdf.scm,
  gnu/packages/pulseaudio.scm, gnu/packages/qemu.scm, gnu/packages/qt.scm,
  gnu/packages/ratpoison.scm, gnu/packages/rdf.scm, gnu/packages/slim.scm,
  gnu/packages/texlive.scm, gnu/packages/version-control.scm,
  gnu/packages/video.scm, gnu/packages/vpn.scm, gnu/packages/w3m.scm,
  gnu/packages/xml.scm, gnu/packages/xnee.scm, gnu/packages/xorg.scm,
  gnu/packages/zip.scm:  Move some build-time dependencies from `inputs' to
  `native-inputs'.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/pdf.scm

@@ -59,7 +59,6 @@
              ("libjpeg-8" ,libjpeg-8)
              ("libpng" ,libpng)
              ("libtiff" ,libtiff)
-             ("pkg-config" ,pkg-config)
              ("zlib" ,zlib)
 
              ;; To build poppler-glib (as needed by Evince), we need Cairo and
@@ -68,6 +67,8 @@
                          (inputs (alist-delete "poppler"
                                                (package-inputs cairo)))))
              ("glib" ,glib)))
+   (native-inputs
+      `(("pkg-config" ,pkg-config)))
    (arguments
     `(#:tests? #f ; no test data provided with the tarball
       #:configure-flags