libungif: remove in favour of giflib

libungif was merged into giflib in 2006, and hasn't been updated
since.  All non-broken packages still using it build fine with giflib.

See <http://giflib.sourceforge.net/history.html>.

pkgs/applications/window-managers/icewm/default.nix

@@ -30,7 +30,7 @@
 , libpthreadstubs
 , libsndfile
 , libtiff
-, libungif
+, giflib
 , libxcb
 , mkfontdir
 , pcre
@@ -81,7 +81,7 @@ stdenv.mkDerivation rec {
     libpthreadstubs
     libsndfile
     libtiff
-    libungif
+    giflib
     libxcb
     mkfontdir
     pcre

pkgs/applications/window-managers/windowmaker/default.nix

@@ -1,6 +1,6 @@
 { lib, stdenv, fetchurl, pkg-config
 , libX11, libXext, libXft, libXmu, libXinerama, libXrandr, libXpm
-, imagemagick, libpng, libjpeg, libexif, libtiff, libungif, libwebp }:
+, imagemagick, libpng, libjpeg, libexif, libtiff, giflib, libwebp }:
 
 stdenv.mkDerivation rec {
   pname = "windowmaker";
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ pkg-config ];
 
   buildInputs = [ libX11 libXext libXft libXmu libXinerama libXrandr libXpm
-                  imagemagick libpng libjpeg libexif libtiff libungif libwebp ];
+                  imagemagick libpng libjpeg libexif libtiff giflib libwebp ];
 
   configureFlags = [
     "--with-x"