Media Mover S3 CDN Improvements

The S3 module for Media Mover just got updated to make the CDN integration easier. As files come through the system, files which already reside on S3 will have $file->s3_uri set which allows theming functions to display the local URI if it is present or the S3 URI if the file is already on S3.

Make that $file->s3_data which is a serialized array of data from the S3 file. This allows for the generation of private urls.