Undo/Redo buttons cause "Uncaught TypeError: boolean is not a function" to appear in console

[bmac]

This can be reproduced by navigating to http://hallojs.org/demo/markdown/, opening the console then clicking the undo or redo button. The text "Uncaught TypeError: boolean is not a function" to appear in the console.

It looks like the problem is in button.coffee. The _init function expects @options.queryState to be true or a function. Unfortunately several plugins set the query state value to false.

I have created a temporary workaround for this problem here https://github.com/bmac/hallo/commit/580684318fc1808a0224236fe6ec812782c8eb99