In a parameteric plot, for each sample, draw an approximation of the
shape given by the parametrised intermediate values instead of a
bounding box for these values.
Fix crash when plotting enclosure while aggregating very small segments
and the function is undefined on some segments.
Use a rough and unsafe range evaluation when determining how many times
to iterate Picard operator and whether to split or not.
Do not use rough range evaluation but a safe evaluation when reporting
final result.