message: drakefile: Update zlib to 1.2.9 (released dec 31 2016)
diff: @@ -223,7 +223,7 @@ def configure(cxx_toolkit = None,
  ## Zlib ##
  ## ---- ##
  - zlib_version = '1.2.8'
  + zlib_version = '1.2.9'
  zlib_basename = 'zlib-%s' % zlib_version
  zlib_tarball = drake.node('zlib/%s.tar.gz' % zlib_basename)
  zlib_prefix = drake.Path('zlib')
  