Removing doubled vertecies.

[Kaldarasha]

It would be good if we could remove doubled vertecies. Doubled vertecies are two (or more) vertecies which have the same position and are in the same group. These vertecies are garbage and have no real use. I have no idea which process does create them, but I can clean a lot of them in Blender. Though, I guess with my colouring in Kimera, I produce new one or maybe they are created in the converting process from a .3ds file to a .p file.