Add Redshift Manifest functionality

Add [Redshift Manifest](http://docs.aws.amazon.com/redshift/latest/dg/loading-data-files-using-manifest.html) functionality to the Pipeline.

* S3ManifestEmitter for uploading files to S3 and putting S3 Path on output stream
* RedshiftManifestEmitter for gathering S3 file paths and combining them into a Manifest file

![redshift_manifest_pipeline](https://cloud.githubusercontent.com/assets/739782/5332993/6a543930-7e1e-11e4-9537-8e6f4e4e0531.jpg)