new layout code
* clutter/clutter-texture.c (clutter_texture_new_from_actor): Now
parents the source actor if it doesn't already have a parent so
that it will get an allocation during layout.
* tests/test-fbo.c: One of the tests tries to ensure that the
ClutterTexture clone keeps the source actor alive by derefing
it. However as actors have a floating reference then test-fbo
doesn't have its own reference once the source is parented so
unrefing just steals the parent's reference and causes
badness. The test now claims the floating reference before cloning
the source so that it can safely be unref'd later.