Add ability to replace [data-editor] element instead of appending

I started work on https://github.com/powmedia/backbone-forms/issues/302 and the first thing i ran into is the extra `<span data-editor></span>` elements that are left around.  Bootstrap requires unwrapped `<input class="form-control" />`s to be at the same depth as `.help-block` and features like input group addons.