xorg: libXfont, libxkbfile: add zlib dependency.

component/xorg/buildout.cfg

@@ -268,6 +268,8 @@ md5sum = 6851da5dae0a6cf5f7c9b9e2b05dd3b4
 environment =
   PKG_CONFIG_PATH=${fontsproto:location}/lib/pkgconfig:${libfontenc:location}/lib/pkgconfig:${xproto:location}/lib/pkgconfig:${xtrans:location}/share/pkgconfig:${freetype:location}/lib/pkgconfig
   PATH=${pkgconfig:location}/bin:%(PATH)s
+  CPPFLAGS=-I${zlib:location}/include
+  LDFLAGS=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib
 
 [libxkbfile]
 recipe = slapos.recipe.cmmi
@@ -276,6 +278,8 @@ md5sum = 19e6533ae64abba0773816a23f2b9507
 environment =
   PKG_CONFIG_PATH=${kbproto:location}/lib/pkgconfig:${libX11:location}/lib/pkgconfig:${libXau:location}/lib/pkgconfig:${libxcb:location}/lib/pkgconfig:${xorg-libpthread-stubs:location}/lib/pkgconfig:${xproto:location}/lib/pkgconfig
   PATH=${pkgconfig:location}/bin:%(PATH)s
+  CPPFLAGS=-I${zlib:location}/include
+  LDFLAGS=-L${zlib:location}/lib -Wl,-rpath=${zlib:location}/lib
 
 [xkeyboard-config]
 recipe = slapos.recipe.cmmi