* clutter/clutter-alpha.h:
* clutter/clutter-alpha.c: ClutterAlpha is an initially
floating object, as it makes sense only when bound to
a ClutterBehaviour; add checks for public API.
* clutter/clutter-behaviour.h:
* clutter/clutter-behaviour.c: Remove the ClutterBehaviour
constructor: ClutterBehaviour is an abstract class which
must be implemented by subclassing; add checks for public
API; unref the actors on finalize; sink the ClutterAlpha
object.
* clutter/clutter-behaviours.h: ClutterKnot is a boxed
type: add the _get_type() function declaration and the
type macro.