[util][math] add sqrt function in bg::math namespace; this function
calls std::sqrt for fundamental number types and ::sqrt for everything
else; it helps avoiding implicit conversions for fundamental number
types when ::sqrt is called (in particular, we avoid the conversion
from long double to double when ::sqrt is called);
[util][math] update copyright header
[strategies] replace calls to ::sqrt by calls to bg::math::sqrt
[strategies] fix unused typedef warningy
[algorithms][equals] fix copyright years; replace call to ::sqrt
by call to bg::math::sqrt
[extensions] replace calls to ::sqrt by calls to bg::math::sqrt;
change has not been applied to projections and ttmath;
[extensions][algorithms][offset] remove obsolete include (file no
longer exists)
[util][math] fix return type of sqrt for fundamental number types
Merge branch 'develop' of https://github.com/boostorg/geometry into feature/math-sqrt
Merge branch 'feature/math-sqrt' of github.com:mkaravel/geometry into feature/math-sqrt
[buffer] Classify turn-points using rescaled rings
This makes side_on_convex_range and intersection_side redundant
It fixes all but one (p20) remaining cases for polygons
Merge branch 'develop' of github.com:boostorg/geometry into develop
[for_each] Move from multi/ and drop TypeOf dependency
[unique] Move from multi/ and drop TypeOf dependency
[transform] Move the code from multi/ and drop TypeOf dependency
[reverse] Move the code from multi/ and drop TypeOf dependency
[algorithms] Move the code of some algorithms from multi/ and drop TypeOf dependency.

Algorithms moved: correct, envelope, equals, length, num_geometries, perimeter, remove_spikes.
[algorithms][multi] Move the code of some algorithms from multi/ dir and drop TypeOf dependency.

Modified algorithms: area, centroid, clear, convert, length, perimeter, simplify.
Update included headers paths to reflect the changes.
[point_in_geometry] Fix compilation error - replace BOOST_AUTO_TPL - drop TypeOf dependency
[test] Fix compilation error in pythagoras distance strategies tests - missing TypeOf header