added sequential edition backend storage entity
CS fixe
PIM-3148: Create a mass action route for sequential edit
CS fixes
blank space removed
Merge pull request #1440 from akeneo/3136

PIM-3136: added sequential edition backend storage entity
Merge pull request #1441 from akeneo/PIM-3132

PIM-3132: Add button for sequential product edition
PIM-3146: Add acl resource on sequential edit button
PIM-3146: Add AclAncestor on mass action
PIM-3136: Update SequentialEdit.orm.yml
Merge pull request #1443 from akeneo/PIM-3136

PIM-3136: Update SequentialEdit.orm.yml
Merge pull request #1444 from akeneo/PIM-3146

PIM-3146: Manage ACL
Remove useless code
PIM-3151: Add notification factory, manager and specs for it
Merge branch 'master' into fix/PIM-3121

Conflicts:
	CHANGELOG.md
Merge pull request #1433 from akeneo/fix/PIM-3121

Fixes memory leak on generic Doctrine Writer
Merge branch '1.2'
WIP first POC on product PDF generation
WIP add a compiler pass and tagged generators
Merge branch 'PIM-3131' of github.com:akeneo/pim-community-dev into PIM-3131