Added ProductAttributeInterface
Corrected flexible entity config
Corrected validation
Corrected bugs in form types
Corrected bugs in ProductAttributeController
Fixed bugs in form types
Corrected bug in DI
Corrected form type instanciation
Corrected type instanciation
Merge branch 'master' into task/product_attribute_interface

Conflicts:
	src/Pim/Bundle/CatalogBundle/Entity/Completeness.php
Fixed PHPDoc
Merge pull request #580 from akeneo/task/product_attribute_interface

Task/product attribute interface