OSG list multipart uploads fixes

Added KeyMarker, UploadIdMarker, NextKeyMarker and NextUploadIdMarker elements to the response.
Ordered the listing by keys first and upload IDs next.
Added the binding for upload-id-marker and max-uploads.
Fixed listing logic when key-marker and upload-id-marker are incldued in the request.
Ignored upload-id-marker when key-marker is not available in the request.
Changed Initiator ID to user ARN.

Fixes EUCA-9443