s3fs 7.x-2.0

The major version number has been bumped because THIS VERSION IS NOT 100% BACKWARDS COMPATIBLE WITH s3fs 7.x-1.x!!
99% of the functionality will work on a site originally set up using 7.x-1.x, but Partial Refresh Prefix will break, because it's been replaced with the Root Folder setting.

NEW FEATURES in S3 File System 2.0:

1) S3 File System 2.0 can now take over the public:// and private:// filesystems, ensuring that even hardcoded public:// files will be stored in S3. This has some major implications for CSS and Javascript files, though, so you'll need to be able to configure your webserver to act as a proxy for them, as described in the README.
2) The Partial Refresh Prefix option has been replaced with the Root Folder option. Root Folder allows you to configure s3fs to put every file it writes into a specific subfolder of your bucket. This will allow a single bucket to host multiple different Drupal sites' files, and it makes the feature work better with public:// takeover and image derivatives. "Root Folder" provides the same functionality as Partial Refresh Prefix, but it is not backwards compatible with Partial Refresh Prefix! So if you were using Partial Refresh Prefix, you'll need to read the README.txt file for instructions on how to upgrade.
3) Support for CORS uploads is now available through the S3 File System CORS Upload module. With that module installed, you can set your File fields to use a new widget which will upload the file to S3 directly from the user's browser. This will provide an enormous performance boost for uploads, as the Drupal site will no longer need to act a middleman for the file's trip to S3.

BUGFIXES:
Uninstalling s3fs will now properly delete its variables.
Issue #2404939: Bucket Name Authentication Failure: "Authorization header is invalid"
Issue #2399665: Using PHP copy() to s3:// doesn't cause error if the bucket doesn't exist
Issue #2381007: Support for AWS region eu-central-1