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.
Previously, the Cogl backend was at times a subclass of the X11
backend, and at times a standalone one. Now it is the other way
round, with GDK and X11 backends providing the concrete classes,
layered on top of the generic Cogl backend. A new EglNative backend
was introduced for direct to framebuffer rendering. This greatly
simplifies the API design (at the expense of some casts needed)
and reduces the amount of #ifdefs, without duplicating code.
https://bugzilla.gnome.org/show_bug.cgi?id=657434
This commit introduces a new flavour for Clutter, that uses GDK
for handling all window system specific interactions (except for
creating the cogl context, as cogl does not know about GDK), including
in particular events. This is not compatible with the X11 (glx)
flavour, and this is reflected by the different soname (libclutter-gdk-1.0.so),
as all X11 specific functions and classes are not available. If you
wish to be compatible, you should check for CLUTTER_WINDOWING_X11.
Other than that, this backend should be on feature parity with X11,
including XInput 2, XSettings and EMWH (with much, much less code)
https://bugzilla.gnome.org/show_bug.cgi?id=657434
