population implemented, renderer adjusted as such, and 100+ other changes
20230110 - first in-field testing seems good
20221228
base population class initted
20221215
20221001
extract array of tuples, the (X,Y,U) of the XYU bubble chart
update: herwig van ranst - 2021.12.30: setSceneMethod::LABEL_Y and LABEL_Z attribute added