Fix drawing correspondences

Fixes #367 

:warning: **Work in progress** :warning:

Commit by commit:
- Fix the variant where the user provided a `std::vector`, it wasn't working at all.

- An additional line was drawn between last point and (0,0,0) when the correspondence size was smaller than the cloud size. The color affectation was also wrong, I replaced it with a simpler method (using only VTK)

Todo list:
- Add viewport information in line drawing
- Test with VTK 5.8, 6.1, 6.2