More work on attr re-binding.
Merge branch 'master' of github.com:aaronc/freactive

Conflicts:
	src/clojure/freactive/dom.cljs
Have working diff algorithm in this commit - but! in my tests in Firefox and Chrome, DOM replacing outperforms diff updating - maybe the algorithm can be optimized, but probably because I am using Clojure data structure as the virtual DOM, this causes a big hit and possibly also the fact that reactive computations need to be stopped. For now, diffing will stay off.