Add busybox component.

component/busybox/buildout.cfg

+[buildout]
+
+parts = busybox
+
+[busybox]
+recipe = slapos.recipe.build
+url = http://busybox.net/downloads/busybox-1.19.3.tar.bz2
+md5sum = c3938e1ac59602387009bbf1dd1af7f6
+script =
+    extract_dir = self.extract(self.download(%(url)r, %(md5sum)r))
+    workdir = guessworkdir(extract_dir)
+    self.logger.info("Creating default configuration")
+    call(['make', 'defconfig'], cwd=workdir, env=env)
+    self.logger.info("Building")
+    call(['make'], cwd=workdir, env=env)
+    self.logger.info("Installing")
+    call(['make', 'CONFIG_PREFIX=%(location)s', 'install'], cwd=workdir, env=env)
+    self.logger.info("Installation finished")