Issue #1996736 by Dave Reid: Add support for hook_migrate_api_alter()
Issue #1996602 by mikeryan: A default field handler is now provided that should handle many if not most field types without custom handlers
Issue #1986742 by mikeryan: Move all modules to Migration package
Issue #1996350 by mikeryan: Fix side-effect of sourceMigration support, setting source fields DNM caused sourceMigration changes
Issue #1996350 by mikeryan: Allow sourceMigration to be edited
Issue #1996280 by mikeryan: Allow all field/subfields/options to be edited, and indent subfields/options to make the relationship more clear
Issue #1990760 by mikeryan: Replace unimported with unprocessed for accuracy
Issue #1989012 by mikeryan: Support preserve_files for MigrateFileFid
Issue #1982564 by Luxian: Properly handle messages for ignored rows
Issue #1989022 by mikeryan: Strip HTML tags from drush fields output