[turns] rename less functor from less_seg_dist_other_op to less_seg_fraction_other_op (to indicate that the fraction comparison is now used)
[test][set ops] separate tests with multiple points as different test cases
[test][set ops] separate test with duplicate points as different test cases; add test cases with spikes;
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/setops
[test][difference L/L] add a couple more test cases of geometries with spikes
[copyright headers] unify the way they look
[algorithms][overlay] allow for spikes in output likestrings; this modifies the behavior of existing set ops and allows to support linear geometries with spikes;
change copy_segments for linestrings to take a template parameter to control whether spikes are accepted or not; by default they are not accepted
(but the follow code now explicitly allows for them in places where it wasn't;
[overlay] add template parameter to follow and action_selector about removing spikes; the default behavior is to remove them; this is backward compatible with the
code before the changes in copy_segments
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/setops
[concatenate_iterator] make the iterator bidirectional
[point_iterator] fix constructor calls for concatenate_iterator
[concatenate iterator] re-factor unit test; add tests for bidirectional iterators;
[test][iterators] added copyright header
[test][iterators] re-factor test code for flatten and concatenate iterators
[test][point iterator] re-factor test code; add tests for points_front, points_back, points_reverse_iterator; test point_iterator as bidirectional iterator
[point_iterator] add free functions points_front and points_back that return the first and last point of a geometry
[flatten_iterator] implement decrement operation for flatten iterator
[point_reverse_iterator] implement reverse iterator for geometries
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/point_iterator
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/setops