+Common code I use in some GAE projects, it provides:
+ - Basic folder hierarchy.
+ - Sending emails using queues using gae, or sendgrid with a http remote request.
+ - Previewing emails in the browser.
+ - Shorting urls using bit.ly.
+ - Decorators to cache using memcache and/or cachepy.
+ - Decorator to cache urls.
+ - Decorator to limit the requests by url, time and ip.
+ - Decorator to retry a function call when it fails.
+ - Some helpers to validate and filter params.