mod: InnerNodeLike/InnerEdgeLike renamed to InnerNode/InnerEdge, common base InnerElem added
mod: InnerNodeLike/InnerEdgeLike renamed to InnerNode/InnerEdge (2)
mod: GraphParam*, NodeIn/EdgeIn, NodeOut/EdgeOut templates renamed to *Param, OuterNode/OuterEdge, InnerNodeParam/InnerEdgeParam, resp.
mod: method names toEdgeIn, to NodeInSet, toEdgeInSet changed to toOuter for clarity and uniformity
new: Traverser, deprecations
new: LDiEdge with mutable label