IAM ARNs always have a blank region

http://docs.aws.amazon.com/IAM/latest/UserGuide/Using_Identifiers.html
resource -> service, data -> resource

To match the ARN & Namespaces conventions found here:

http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html

Also added an ARN class to S3, and ditched region for IAM per the IAM
docs.
Merge pull request #1 from cloudtools/update_arns

Update arns