PIM-2234 : add methods in ProductCategoryRepositoryInterface to filter
products by categories
PIM-2234 : phpdoc
PIM-2234 : fix category filters
PIM-2234 : write simpler methods to filter products by categories
PIM-2234 : fix cs
Merge pull request #1313 from akeneo/PIM-2234

PIM-2234 : add methods to filter products by categories