CVS import. First, fixed sig::next regarding two things. One, we have to take the root version of a file into account as a possible predecessor. Two, a missing changed file may be misclassified and actually be added instead. Second, modified the search for a root changeset of a branch. We now try the existing regular intersection first for exactness, and in case of failure we fall back to a voting scheme to locate the most acceptable aka non-conflicting changeset.