New recipe covering how to animate rotation of
an actor (in all axes).
Covers various factors affecting rotation animation
(like orientation of axes, parent rotation/orientation),
as well as trying to make rotations easier to visualise
(e.g. describing how rotation direction is affected by
those factors, how a rotation can be expected to look
when animated). Uses implicit animations for code examples.
Also refers to a full code example which uses ClutterState.
Introduces basic concepts (timelines, alphas, frames)
common to different parts of the Clutter animation API.
Gives a high level overview of the three different
approaches to animation (implicit, ClutterAnimator,
ClutterState).
Added a new recipe (based on the skeleton in the
animations section of the cookbook) about inverting
an animation by reversing the direction of its timeline.
Uses clutter_actor_animate() as the basic approach,
but mentions ClutterState and ClutterAnimator as well.
