revert: drop now useless conditional in the backup check Now that we removed the (hopeless) attempt to backup file we knew to be missing in the target changeset, we can stop checking if the file exists in the target changeset.

revert: no backup for `dsadded` set There is only one case where a backup is required in the `dsadded` set, and the current backup mechanism fails to handle it. So we stop trying to do backups at all for now. This will help us to simplify the backup code and finally fix this backup issue.

revert: add more padding in the dispatch list We are going to add more sets and some of them will have longer names. We add padding in a standalone patch for readbility purposes.