ngAnimate overwrites ngStyle

[hswolff]

Ran into this after upgrading to 1.2.0 today (congrats btw :)).

Basic issue is that the new updates to ngAnimate to prevent elements from entering a stale state (by applying transition: none) is overwriting any styles applied on that element, rather than appending.

Have a look at this plunkr: http://plnkr.co/edit/PMxVTydp4b2tVt5ZhD09?p=preview

If you hover your mouse over the element it should remain black, however it turns back to red after a moment.

Seems ngAnimate overwrites the styles and then ngStyle is reapplied resulting in the red background appearing again.

[petebacondarwin]

Moving discussion to #4869