v0.10.3

• Add FOLD.filter.cutEdges for cutting apart ("unwelding") edges in 2D crease pattern, using vertices_edges
• vertices_edges manipulators:
  • Add FOLD.convert.vertices_edges_to_faces_vertices_edges
  • Add FOLD.convert.edges_vertices_to_vertices_edges_sorted helper
  • Add FOLD.convert.edges_vertices_to_faces_vertices_edges helper
  • Rename FOLD.convert.edges_vertices_faces_vertices_to_faces_edges to FOLD.convert.faces_vertices_to_faces_edges.
• Helpers:
  • Add FOLD.filter.addVertexLike similar to FOLD.filter.addEdgeLike (for vertex duplication)
  • Re-order arguments of FOLD.filter.addEdgeLike (for edge duplication)
  • Add FOLD.convert.deepCopy for deep copying fold structures
  • Improve FOLD.filter.numType (and thus FOLD.filter.numVertices) to use ..._type keys when there are no type_... keys.
  • Change filter.edges_verticesIncident to return common vertex when the answer is "yes" (instead of true), and null otherwise (instead of false).
• Update documentation