Ideally `label` isn't a lazy attribute, but `label`'s setter can't properly execute until `this._host` is set, which doesn't occur until a few lines before this one in the initializer....

... and nevermind, I just found the solution.  ButtonCore should try to populate `this._host` with `this.get('boundingBox')` if it isn't already set.

Oh, and the `disabled` setter can also be removed.  After some experimentation, https://github.com/yui/yui3/pull/406/ did fix targeted issue, but executing `disabled`'s setter in the initializer wasn't required.  I think at least.  Regardless, it works as expected now.

So looks like I can actually remove this entire method now.  Update coming soon.