[Amibe] Skeleton: bug fix
[Amibe] VertexInsertion: better failure reporting
[Amibe] QEMDecimateHalfEdge: minor change
[Amibe] TriangleKdTree: do not fail when projecting on degenerated triangles
[Amibe] Skeleton: remove a bad assert
[Amibe] RemeshSkeleton: better selection of vertices to keep
[Amibe] DistanceMetric: let d1 be computed automatically for lines

when d1 <= d0.