Fix for #147

I've updated the format value functions to allow a 0 value to be bound to inputs. I also updated a test in test-form to cover the case, and re-included this file in test-browser. (I guess you may want to un-include this from test-browser again)

Hopefully this PR includes only the correct files!
Hmm I suppose, but in my case I'm binding the form with some object that I've retrieved from an ORM, which has numerical values. Have I just been using it wrong? :)