component/macros.cfg: Create a new macro with pygolang

Using macros.cfg to add a new macro.
This macro will works like [macro-virtual-env].
Neverthless, it will use pygolang to create a more "classic" interpreter.

component/macros/virtual-env.cfg

+[buildout]
+extends =
+	../pygolang/buildout.cfg
+
+[virtual-env-base]
+recipe = slapos.recipe.build
+_name = ${:_buildout_section_name_}
+init =
+  from zc.buildout.easy_install import working_set
+  import os
+  name = options['_name']
+  eggs = options['eggs']
+  try:
+    scripts = "scripts = " + options['scripts']
+  except KeyError:
+    scripts = ""
+
+  self.buildout.parse("""
+  [.%(name)s.install-eggs]
+  recipe = zc.recipe.egg
+  eggs = %(eggs)s
+  %(scripts)s
+
+  [.%(name)s.install-interpreter]
+  <= python-interpreter
+  eggs += %(eggs)s
+  """ % locals())
+install =
+  with open(location, "w") as f:
+    f.write(options['template'] % {
+      "path" : self.buildout['buildout']['bin-directory'],
+      "name" : self.name,
+    })
+
+# Template virtual env for bash shell in posix
+[virtual-env-base:posix]
+template =
+  deactivate () {
+    set PATH PS1
+    while [ "$1" ]; do
+      eval "if [ \"\$_OLD_VENV_$1\" ]; then $1=\$_OLD_VENV_$1; else unset $1; fi; unset \$_OLD_VENV_$1"
+      shift
+    done
+    unset -f deactivate
+  }
+
+
+  VENV_PATH=%(path)s
+  _OLD_VENV_PATH=$PATH
+  _OLD_VENV_PS1=$PS1
+  PATH=$VENV_PATH:$PATH
+  PS1='(%(name)s) '$PS1