Add cros-unzip.py to allow to unzip in ChromeOS in developer mode as Guest

cros-unzip.py

+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+"""
+  Extracts files from a .zip container to the current working directory.
+
+  http://stackoverflow.com/questions/7806563/how-to-unzip-a-file-with-python-2-4
+"""
+import sys
+import zipfile
+zfile = zipfile.ZipFile(sys.argv[1])  # Usage: unzip ZIPFILE
+zfile.extractall(".")
+zfile.close()