The previous behavior is plain wrong, since that array has always at least one
element, so we effectively couldn't specify anything else than "ease" in our
animations.
So this actually allows some more animations to be triggered. The bad part of
this is that they're actually triggered always when the style is recalculated,
so we're going to have at least some more state into the node, and the
constellation, which would have to keep track of the animations states.
