Cut ${ZESHY_USER_DIGEST_..._MTIME} from @{digest}.

Cutting integer global ${ZESHY_USER_DIGEST_FILE_DEPENDENCY_NEWEST_MTIME} from
@{digest} has the benificial side effect of substantially reducing the
complexity of such parcel. Indeed, doing so appears to have already eliminated a
number of nagging regressions. "So be it, integral codebase!"