Remove the layout containers: they will be moved to a
high-level library.
* clutter/clutter.h:
* clutter/Makefile.am: Remove layout and boxes from the
build.
* clutter/clutter-layout.[ch]: Remove the ClutterLayout
interface.
* clutter/clutter-box.[ch]:
* clutter/clutter-hbox.[ch]:
* clutter/clutter-vbox.[ch]: Remove ClutterBox and its
subclasses.
* clutter/clutter-label.c: Remove ClutterLayout implementation
* clutter/clutter-script-private.h:
* clutter/clutter-script-parser.c:
* clutter/clutter-script.c:
(clutter_script_parse_node): Remove special parsing for
ClutterMargin and ClutterPadding.
* clutter/clutter-types.h: Remove ClutterPadding and ClutterMargin.
* tests/Makefile.am:
* tests/test-boxes.c: Remove the boxes test case.