slapos: add referenced extends explicitly.

component/slapos/buildout.cfg

@@ -2,14 +2,25 @@
 [buildout]
 extends =
   ../../stack/slapos.cfg
+  ../bison/buildout.cfg
+  ../bzip2/buildout.cfg
+  ../firewalld/buildout.cfg
   ../gdbm/buildout.cfg
   ../gettext/buildout.cfg
+  ../glib/buildout.cfg
+  ../libxml2/buildout.cfg
+  ../libxslt/buildout.cfg
   ../m4/buildout.cfg
+  ../ncurses/buildout.cfg
+  ../openssl/buildout.cfg
+  ../patch/buildout.cfg
+  ../pkgconfig/buildout.cfg
+  ../popt/buildout.cfg
   ../python-2.7/buildout.cfg
+  ../readline/buildout.cfg
   ../sqlite3/buildout.cfg
   ../swig/buildout.cfg
-  ../patch/buildout.cfg
-  ../firewalld/buildout.cfg
+  ../zlib/buildout.cfg
 
 parts =
   slapos