Porting to new API + qanimationframe, adapting tests, improve README

Here is an implementation of the new API, Test should pass, however I had to remove some of them because of API changes.

I also took some choices we can discuss:

**I added QanimationFrame dependency** and use it for the "transition" and the "set attribute" API usage, which also have the benefit of catching `elt.style[attr]=value` exception which can happen on IE.

**I chosed to prefer to throw Error as much as possible** instead of returning a failure Promise because those are easier to detect (generally because of bad Zanimo API usage), once the Zanimo call is wrapped in a Promise the exception is obviously transformed into a Failure promise.

Things to be done:
- While we now have an API for setting a CSS style, It would be a good idea to depends on a proper prefix library to have all CSS properties working. When migrating to this prefix library, we will have to refactor/clean the T object, and I suggest we don't expose it anymore.
- I haven't migrate the main index.html but I think you want to remove it according to #7


Please don't merge it yet, we will have to test it more and maybe we can refactor the prefix part as previously said ;)

Thanks