Fix wrong reference after renaming.
Docstrings and PEP8 stuff.
Don't let Filament inherit from Points3D.
Add ToDo.
Check if path endpoints are connected.
Build path upon object construction.
Add Filament.splitpaths().
Calculate path length (requires a p3d object).
Cosmetics.
First prototype of "CellJunction" class using the new "Filament" object.