Include argparse in py26 bundled install

Also removed dead code and used a unique venv
directory to create the bundled install each time.
This makes it possible to run scripts/make-bundle
multiple times.
Fix install script bug for error conditions

When an error occurs, stderr was None because of
stderr=subprocess.STDOUT.  Now we just use subprocess.PIPE
so we can only include stderr in the error case.
Actually zip the bundled dir

As the function say it's suppose to do :)
Merge branch 'py26-bundle-install' into develop

* py26-bundle-install:
  Actually zip the bundled dir
  Fix install script bug for error conditions
  Include argparse in py26 bundled install