[button] Don't use destroy, use unparent
[button] Don't use destroy, use unparent

Because we're a container, calling destroy ends up calling our
container_remove function. There's a new internal-child property that
will stop this, but we need to work on Clutter 1.0, so call unparent
instead.

jonnylamb/mx,jonnylamb/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,clutter-project/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,pwithnall/mx,pwithnall/mx