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

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.

Don't use URL to get XML file since thats not too reliable working through drush. Use file path instead ... Fix for directory creation in Field plugin