Revert all the work that happened on the master branch.
Sadly, this is the only way to merge the current development branch back
into master.
It is now abundantly clear that I merged the 1.99 branch far too soon,
and that Clutter 2.0 won't happen any time soon, if at all.
Since having the development happen on a separate branch throws a lot of
people into confusion, let's undo the clutter-1.99 → master merge, and
move back the development of Clutter to the master branch.
In order to do so, we need to do some surgery to the Git repository.
First, we do a massive revert in a single commit of all that happened
since the switch to 1.99 and the API version bump done with the
89a2862b057423c3c1fc666e6fa776ccacf377dd commit. The history is too long
to be reverted commit by commit without being extremely messy.
During the gutting of ClutterBox, the destroy and dispose implementation
were removed. The former, especially, destroyed all children - which
usually meant that the redraw queues for the childre was cleared as
well. The removal introduced crashes when a Box was destroyed while its
children were still queueing redraws.
This will make things interesting.
We have better replacements in ClutterActor, that do The Right Thing™
instead of deferring control and requiring reimplementation in every
single container actor.
ClutterBox functionality has been implemented by ClutterActor, and
proxied by the Box subclass; with the removal of the abstract bit on
ClutterActor, we can safely deprecated ClutterBox.