tree editor UI

[KevinField]

With drag-n-drop, colour picker, and image uploader.

[KevinField]

We'd have to be a bit careful with a normal tree editor interface, that it remains intuitive to use, and that updates to one section happen to all of its extra references: even with a loop checker, our data may not be a tree: menu 1 could refer to menus 2 and 3, but menu 2 could also refer to menu 3, for example, and in a directed graph sense this is not a loop. Should this be allowed or should everything have to be a proper tree (not just for the sake of a tree editor UI, but the end user also)?