Uncommented changes: backing up

TODO.md

 - pass counting_factor from get_correction_factors down get_correction_factor.
   check_tree to get_boundary_radiusß
+- pass counting_factor and area to each call of get_r_max(). Via an option?
 - redesign check_boundaries: goes_through_origin should be only on thing in it.
   The message should come from goes_through_origin?
 - pass number of n-gon down to circle2polygon via option?