Initialize value to remove warning; only shift graph label if set.
Fix cccomps to provide a mapping from the cloned clusters in the derived components to the
original clusters. This allows an application to easily reconstruct the cluster tree and to
move info from the cloned cluster to its real counterpart.
Use real root to check if labels exist, as this is where the bits are set.
Fix coding hole when packing disconnected components when clusters are used. We need to
recreate the cluster tree in the top-level graph, and copy position info from a cloned
cluster in a component to the real cluster in the top-level graph. (The clusters in a
component are really copies.);
use graph granularity by default when packing;
clean up layout info in the clusters before deleting them;
add comments on functions;
free cluster labels (this has never been done).