Upgraded class to use with aws-sdk-php v3 (CloudFront functions missing)

[patrickbussmann]

This is only a small preparation so that other users can continue this integration of the aws-sdk-php.
The example wrapper is working with it.
Don't forget to install composers using $ composer install or $ php composer.phar install. (https://getcomposer.org/download/)

For WordPress W3 Total Cache I needed a solution and so this should be enough for it.
Some others facing the same issue: #120 #96
I hope that help's a bit. 👍

[philicious]

@patrickbussmann I just encountered the same problem as you likely had: W3 Total Cache CDN feature failing for S3 Frankfurt region...

Now, if I get you right, your changes to S3.php should be sufficient to fix W3TC ? Or are there any issues/use-cases left that would need to be addressed?

(I could also use a different approach like s3fs for wp-content/ folder but as I use W3TC anyways, the "plugin-way" would be more elegant)