GCC has some optimization for the inclusion guard, but they only work if
the check is the outermost one.
We're fairly inconsistent because of historical reasons, so we should
ensure that we follow the same pattern in every public header.
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
89a2862b05 commit. The history is too long
to be reverted commit by commit without being extremely messy.
ClutterGridLayout is port of GtkGrid to a Clutter layout manager. All
the logic is taken from gtkgrid.c, so all the credits should go to
Matthias Clasen for writing this nice piece of code.
ClutterGridLayout supports adding children with it's own methods
GridLayout.attach() and GridLayout.attach_next_to() as well as
Actor.add_child() and friends. The latter adds children in a similar
fashion to ClutterBoxLayout
https://bugzilla.gnome.org/show_bug.cgi?id=677372
