Clean up extends and extend from slapos stack

component/slapos/buildout.cfg

 # This file is used to install SlapOS Node itself.
-
 [buildout]
-python = python2.7
-
 extends =
+  ../../stack/slapos.cfg
   ../../stack/shacache-client.cfg
   ../bison/buildout.cfg
-  ../bzip2/buildout.cfg
   ../gdbm/buildout.cfg
   ../gettext/buildout.cfg
-  ../glib/buildout.cfg
-  ../libxml2/buildout.cfg
-  ../libxslt/buildout.cfg
-  ../lxml-python/buildout.cfg
   ../m4/buildout.cfg
-  ../ncurses/buildout.cfg
-  ../openssl/buildout.cfg
-  ../pkgconfig/buildout.cfg
-  ../popt/buildout.cfg
   ../python-2.7/buildout.cfg
-  ../python-cffi/buildout.cfg
-  ../python-cryptography/buildout.cfg
   ../readline/buildout.cfg
   ../sqlite3/buildout.cfg
   ../swig/buildout.cfg
-  ../zlib/buildout.cfg
   ../patch/buildout.cfg
 
 parts =
@@ -33,22 +19,7 @@ parts =
   sh-environment
   py
 
-find-links =
-  http://www.nexedi.org/static/packages/source/slapos.buildout/
-  http://www.nexedi.org/static/packages/source/hexagonit.recipe.download/
-
-versions = versions
-
-allow-hosts =
-  *.googlecode.com
-  *.nexedi.org
-  *.python.org
-  alastairs-place.net
-  code.google.com
-  github.com
-  peak.telecommunity.com
 
-unzip = true
 
 # separate from system python
 include-site-packages = false
@@ -132,15 +103,6 @@ interpreter = py
 scripts = py
 
 [versions]
-# Use our own buildout version
-zc.buildout = 1.6.0-dev-SlapOS-012
-
-# Force to use zc.recipe.egg 1.x
-zc.recipe.egg = 1.3.2
-
-# Use own version of h.r.download to be able to open archives not supported by python2.x: .xz
-hexagonit.recipe.download = 1.7nxd002
-
 slapos.core = 1.0.3
 Jinja2 = 2.7.1
 MarkupSafe = 0.18