PIM-3531: rename AttributeHelper to AttributeValidatorHelper
PIM-3531: check existing locale and scope in AttributeValidatorHelper
PIM-3531: rework exceptions for invalid locale or scope in updaters
PIM-3531: rework exceptions for invalid locale or scope in copiers
PIM-3531: remove useless method from setters
PIM-3531: allow copiers to be able to copy from/to different types of data
PIM-3531: fix AttributeValidatorHelper
PIM-3531: fix cs
PIM-3531: fix Behat mass edit
Merge pull request #1925 from akeneo/PIM-3535

PIM-3535: enhance updaters controls