Remove old prepre method in example user migration. It was setting ->created=0 instead of current time.

Remove all the maintainStatistics business from comment import. D6 does not provide optional stats, neither should migrate. If you want that, hack comment_save() and then call devel_rebuild_comment_statistics() in postImport().

Add dedupe() method for a field mapping. This assures that the value is unique, even if source data contains duplicates. Commonly used for usernames. Uniqueness is currently achieved by appending a number (e.g. example1). In the future we can expand to custom replacement patterns such as email address: sally1@example.com. Dedupe can be used on any mapping.