Make scaffold generator produce valid XHTML (transitional) but without any unneeded code (ex. meta tags from Ticket #1364).
I want to produce valid code without adding any extra baggage.
* Added the XHTML Transitional DOCTYPE to scaffold layout (required).
* Added <thead> and <tbody> elements to scaffold list views. (required for XHTML)
* Added a single <fieldset> around all scaffolded fields (required for XHTML).
* Changed <div class="fieldWithErrors"> to <span class="fieldWithErrors"> (Block level elements not allowed in this context. Span will work just the same, as the default style has display:table)
* Wrapped <label> around <input> and <textarea> elements. Not required, but recommended for accessibility.
Working often with strict doctypes, it is annoying to see Active Record errors spitting out invalid code. Also, scaffold code only needed a few tweaks to become valid.
All of these changes make the code valid up to XHTML 1.1, though I left the doctype as transitional to avoid problems.
Updated tests included.
