This reverts commit 49a6aff9.

Since human groups are now stored in their own core segment (as
discussed with Fabian) for clearer distinction between humans and human
groups and a cleaner structure.

Add human tracking

See merge request !68

The current implementation of the KamanFilter does not work with
non-zero orientations.
The detection time to remove humans after a period of not detecting them
wasn't working properly.

as a human group segment does not exist and the writer writes it in the
human segment