Segment type based neighborlist

[baumeier]

Segment type based neighborlist generation is not working. As the default calculator options define a <constant> cutoff, the bool _useConstantCutoff always evaluates to true in neighborlist.cc and the segment type part is never used.

[felipeZ]

@baumeier I think that removing the constant property from the defaults should be enough. I need to add it on the tutorial

[JensWehner]

There are some calculators which change behaviour if a tag is present or not, that collides with having default values.

[felipeZ]

There are some calculators which change behaviour if a tag is present or not, that collides with having default values.

I have removed the default, shall we do something else?

[felipeZ]

solved by #509