PIM-1377 : refactor variant group converter to support many groups
PIM-1377 : add groups field in form type, this fiel is used in import
mode
PIM-1377 : rename groups converter service
PIM-1377 : use the new group converter
PIM-1377 : use the new group converter in the product creation processor
PIM-1377 : fix unit test
PIM-1377 : re-order csv columns
PIM-1377 : update import product scenario
PIM-1377 : take groups in account for csv import of products
PIM-1377 : add missing translation for group column
PIM-1377 : allow to configure groups column for product import
PIM-1377 : fix erroneous variable
PIM-1377 : update demo bundle
Merge pull request #393 from akeneo/PIM-1377

Pim 1377 : import / export product groups
Merge branch 'master' into feature/export_media