Lets you link to files hosted on Amazon s3 so that you can serve secure, expiring download links.
* Tweak: Fixed an S3 secret bug that caused a signature missmatch.
* Feature: Added 'US East (Ohio) - us-east-2' region
* Feature: Added 'Canada (Central) - ca-central-1' region
* Feature: Added 'Asia Pacific (Mumbai) - ap-south-1' region
* Feature: Added 'Asia Pacific (Seoul) - ap-northeast-2' region
* Feature: Added 'EU (London) - eu-west-2' region
* Tweak: Renamed 'US Standard (N. Virginia)' to 'US East (N. Virginia)'
* Tweak: Updated included Amazon S3 libraries.