Merge pull request #50 from mkaravel/feature/distance-default-strategy

[test][strategies] fix compilation errors for pythagoras and haversine unit tests
[strategies][distance] change template parameters' names to reflect
the objects they represent
[geometry][test] Fix concept check failures.

The functions in arithmetic.hpp would check the concepts Point and ConstPoint
on Point2, instead of checking Point on Point1 and ConstPoint on Point2.

This would cause concept check failures when attempting to operate from
a ConstPoint.
Merge pull request #53 from smspillaz/geometry/10077

[geometry][test] Fix concept check failures.
Merge pull request #52 from mkaravel/feature/distance

[strategies][distance] change template parameters' names to reflect the objects they represent
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/distance-default-strategy
[strategies][distance] fix names of template parameters to better
reflect the corresponding objects