Move handling of X11 shapes, X11 opaque/input regions, and X11 unredirection to X11 window actor sub types
Quoting the last commit:
window-actor: Move shapes and unredirection to X11 sub types
Move out updating of various shapes (input, opaque, shape) indirectly
from X11 to the corrpesonding X11 sub types of MetaWindowActor and
MetaSurfaceActor.
Also move fullscreen window unredirection code with it. We want to
effectively do something similar for MetaCompositorServer, but it will
work differently enough not to share too much logic.
While it would have been nice to move things piece by piece, things were
too intertwined to make it feasable.