[geometry][distance] renamed file to a more meaningful name
[geometry][distance] when testing empty inputs, both orders of input geometries is now tested;
[geometry][distance] distance tests for pointlike and linear geometries;
[geometry][distance] added separate test for areal-areal distances;
[geometry][distance] added implementation of distances between two 2D boxes;
[geometry][distance] removed code that was using regular distances for comparison;
[geometry][distance] removed code not using comparable distances;
re-implemented the inner dispatch using the spitted_dispatch namespace;
[geometry][distance] minor: less code for the same thing by using an intermediate typedef;
[geometry][distance] implementation of 2D polygon-box distance;
[geometry][distance] better implementation of the comparable_distance;
now the get_comparable struct is used instead of the comparable_type class;
[geometry][distance] added includes for polygon-box and box-box distances;
[geometry][distance] added separate unit tests for linear-areal and pointlike-areal distances;
[geometry][distance] implemented get_points for 2D boxes;
[geometry][distance] moved 2nd layer dispatch code to dispatch::splitted_dispatch namespace;
[geometry][distance] added missing strategy specialization for point-ring distance;
[geometry][distance] unified range-segment and polygon-segment distance computation with range-box and polygon-box computation;
[geometry][distance] distance_all includes all individual distance_{p,l,a}_{p,l,a}.cpp tests;
[geometry][distance] changed files included, as file names changed;
[geometry][disjoint]
1. added inclusion of multi/algorithms/detail/point_on_border.hpp;
needed by disjoint_linear_areal when the linear geometry is a multi-geometry;
2. fixed specialization of disjoint(polygon, multilinestring);