Let autonomus creatures respawn (reset node position)

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
Bounding circle for collition (eaten) overlap testing

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
minor cleanup

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
cleanup and commenting

Signed-off-by: Alexander Skjolden <alex@plastboks.net>
test snake collition between the other creatures

Signed-off-by: Alexander Skjolden <alex@plastboks.net>