First effort on form validators. Working nicely, but will add more customisation capabilities.
Merge branch 'master' into validation
Updated the required and valid validation messages (also mapped a type of 'url' to the url widget).
Changed the order in which custom attributes are applied. You can now override any attribute on a form input.
Added an input type hidden. Widgets now receive the record and form type.
Merge branch 'validation'

Conflicts:
	lib/formtools/widgets/index.js
	public/css/linz-admin.css
	public/css/linz-admin.styl
fixup