DocumentImport: Keeping Source Images and Index Files together for failed Document Imports.

When there is an error or an issue where a document cannot be imported (other than Account Number, Customer Number, unresolved MTEs, etc.) the index file gets archived, and the corresponding image remains in the _Data folder. Instead of archiving the index file for the failed document import, keep in the index file in the _Data folder with its corresponding image (keep the pair together).