Merge pull request #1663 from akeneo/PIM-3266

PIM-3266: do not flush skipped items during an import
PIM-3282: fix the grid filters that can be set as json in the request
Preparing version 1.2.9
Merge branch 'PIM-3282-stable' into PIM-3282

Conflicts:
	CHANGELOG.md
	src/Pim/Bundle/CatalogBundle/Version.php
Merge pull request #1688 from akeneo/PIM-3282

PIM-3282: fix the grid filters that can be set as json in the request