add ajax save feature.
fix tree merge
Merge branch 'master' into fix_tree_merge

Conflicts:
	src/Innova/LearningPathBundle/Resources/views/Step/includes/list-item-pattern.html.twig
	src/Innova/LearningPathBundle/Resources/views/Step/includes/list-item.html.twig
Merge pull request #44 from arnaudbey/fix_tree_merge

Fix tree merge