Refactor form state storage
Merge branch 'master' into PIM-1642

Conflicts:
	src/Pim/Bundle/UIBundle/Resources/public/js/pim-init.js
	src/Pim/Bundle/UIBundle/Resources/views/require.js.config.html.twig
Clean up form tab and group activation
Fix restoring form tabs and groups with categories and ajax loaded tabs
Merge pull request #555 from akeneo/PIM-1642

Refactor form state storage