Since fetch_url already take care of the exception, the try/except
clause is no longer working, so replace it with proper status
checking, thus permitting to remove urlib2 from the import list.
* Import url(lib|parse|lib2) if needed by the module rather than relying
on module_utils.urls to do so.
* Remove stdlib modules from requirements
* Use the if __name__ conditional for invoking main()
