Circular Reference Serialization in JS (and Java?) Not Handled Gracefully

[MTrop]

Take the following script/module:

action general a_quit named "quit";

world
{
	onAction(a_quit)
	{
		quit;
	}

	start()
	{
		a = [];
		b = [a];
		listadd(a, b);
	}
}

State-saving this structure in Java more-or-less works (?) but the JSON serializer dies with a stack overflow. Must find a way to handle better than just an error message.

Issue is considered low priority - this should not come up much in most modules.