Added support for replication groups to the Amazon ElastiCache client
2.4.5 release
Ensuring that signable querystring parameters are sorted
Merge pull request #144 from aws/s3sigfix

Ensuring that signable querystring parameters are sorted
Make AmazonDb session handler implement native SessionHandlerInterface for >= 5.4
PHP_VERSION_ID was introduced in 5.2.7, so safe to use here.
Merge pull request #143 from pcolby/master

Handle missing / invalid POST data in Aws\Sns\MessageValidator\Message::fromRawPostData, in a way that is much easier to catch / handle.
Merge pull request #145 from datibbaw/sessionhandler-interface

Make DynamoDB session handler implement native SessionHandlerInterface where possible
Added support for VPC features to the AWS OpsWorks client
Updated CHANGELOG after merging PRs
Correcting unit tests
Added ap-southeast-2 to the S3 LocationConstraint enum
Updated EC2 client include RI modification APIs
Updated the version and CHANGELOG for version 2.4.6
Update S3Client.php

Updated DocBlock for getSignature() call to return S3SignatureInterface, because that includes signString().
Bumping API version
Merge pull request #148 from datibbaw/s3client-getsignaturefix

Update S3Client.php
Url encoding query string parameters when creating pre-signed urls for CloudFront http and https URLs. Closes #146.
Updated the Amazon CloudSearch client to use Signature Version 4
Made it easier to add event listeners to waiters.