cvs-fast-export bugs

One paragraph from Keith's original notes is still relevant:

	Disjoint branch resolution. Branches occurring in a subset of the
	files are not correctly resolved; instead, an entirely disjoint
	history will be created containing the branch revisions and all
	parents back to the root. I'm not sure how to fix this; it seems
	to implicitly assume there will be only a single place to attach as
	branch parent, which may not be the case. In any case, the right
	revision will have a superset of the revisions present in the
	original branch parent; perhaps that will suffice.