Add HAML style div syntax

I added a couple lines to the base-element function so that it will support HAML style div creation

````clojure
(def my-element (template/node [:div#elem-id.elem-class]))

;; assumes this is creating a div like haml
(def my-element2 (template/node [:#elem-id.elem-class]))

(assert (== (.-outerHTML my-element) (.-outerHTML my-element2)))
````