'Security' for a special case: When a xyz file contains frames, in which the

'Security' for a special case: When a xyz file contains frames, in which the
number of atoms monotonously increases (due to any reasons), only the number
of atoms of the first frame is used for the animation - the additional atoms,
which appear in following frames, are not drawn! Remember, that the condition
still is: the total number of atoms of each frame must be constant!

Note that the addon crashes when the number decreases.

In future, I try to allow also varying number of atoms in frames. However, this
takes some time since the whole code needs to be re-structured.

Blendphys.