Combine getQuoted- and getUnquotedAttributeValue
HTMLTools: Kill "Special" as a TemplateTag wrapper

Remove the concept of a "Special" as a generalization of template tags in HTML parsing and the HTMLjs tree.  Just call something that's parsed by hooking the HTML parser a TemplateTag.  Don't wrap the return value of getSpecialTag (now getTemplateTag), just require that it be an instanceof HTMLTools.TemplateTag.

Spacebars.TemplateTag is now a subclass of HTMLTools.TemplateTag.  Both support `.toJS()`.  The same object returned by getTemplateTag is now inserted into the HTMLjs -- that is, the Spacebars compiler creates an HTMLTools.TemplateTag instead of it being created as a wrapper inside HTMLTools.  All usages of the words "special" or "special tag" are replaced with "template tag."