Template settings override fix

Hi

I have encounter a problem with `request.reply.view(template, context, options)`.
I basically want one handler to disable the global layout whether the request is ajax or not (fancybox stuff).

I edited the hapi code to be able to do `request.reply.view('myTemplate', {foo: 'bar'}, { layout: !isAjax });`.

I don't feel enough comfortable with hapi yet to write tests on the change, so I didn't, apologize. The pull request is just a fix I did to make it work locally.