VisualScript does not seem to have the ability to get AutoLoad singletons

**Godot version:**

Godot 3.1 Beta

**OS/device including version:**

Windows 10

**Issue description:**

I use VisualScript for quick GUI logic, and I've realized that I can't seem to find a way to get Godot to let me get/type the node path of an AutoLoad singleton into Get Scene Node, so I can't use it to call a singleton function.
I also cannot call get_root() from get_tree().

Update: I can use a sequence of get_parent() to get the desired function or use some other hacky ways. Get Scene Node also doesn't work if the node selected is not a direct child, it seems.

Update 2: Seems with the get_parent() business I can just get a direct node path using Node.get_node(). Getting there is not very intuitive, but once you know it, it should work fairly well.

Update 3: These new methods seem to return null though, so... not very helpful.