todo_item parent update behaviors

[benlubas]

I'm not sure when this changed, or exactly what broke it, but parent items used to update when a keybind was used to change a child state, and sometime around the keybinds refactor, this broke (bisecting to an exact commit is tricky b/c there are multiple commits where the plugin fails to load around this time).

I took this opportunity to make this behavior configurable, b/c personally I've always hated it :P