Significant refactor to consume untranslated API definitions.

Major changes:
* A Seahorse::Model now consumes the raw AWS API descriptions.
* Added support for recursive shapes.
* Added support for shape references.
* Added EndpointProvider with a default set of rules for building regional endpoints.
* Removed API translator.
* Now exposing all types as shapes, no longer reducing them
  down to Ruby native types (e.g. integer & long, string & char)
Added support to Aws::S3 for server-side encryption with customer-provided keys.
Added support to Aws::ElasticTranscoder for captions.
Added taggign support to Aws::ElasticBeanstalk client.
Added support to Aws::EMR for service roles.
Added support to Aws::OpsWorks for RDS instances.
Doc updates for Aws::Redshift.
Added support for message attributes to the Aws::SNS client.
Updated Aws::STS API model.
Removed required trait Aws::Route53 for create health check ip address.
Updated Aws::EC2 client from 2014-02-01 to 2014-05-01 API version.
Initial commit for resource interfaces.