hello world example added
basic initial ring showing: main thing learned is that verlet lib does not like particles whose initial positions are the same (they just do not show)
pulled out _placeInCircleAroundOrigin
pull out radius as an argument
add concentric layer layout
radius increment is actually incrementing an angle, so rename
got layer linking action happening
play about with friction, stiffness
remove some guff
take color from lSystemNode