New Behat tests on grid completeness
Fixes too many flush from versionning and PIM-2916
CS Fixes
Fixes phpDoc and function visibility
Merge branch 'master' into PIM-2916

Conflicts:
	CHANGELOG.md
Merge pull request #1262 from akeneo/PIM-2916

PIM 2916  - MongoDB Completeness in the grid is lost after saving the product