unbound links and forms

[wenzowski]

As requested by Mario Micklisch unbinding forms and links should be possible, and I'm happy to put together a PR to the MarkupProcessor to allow this. I would personally consider using this feature for financial data that I don't want touching Racer.

I'd like to propose data-unbind="true" as the attribute for this, but would appreciate feedback from @nateps before proceeding.