Move Point data type, class and functions into their own module Elements.Point
Move Line data type into own module Elements.Line
Move Polyline data type and functions into own module Elements.Polyline
Move Polylgon data type and functions into own module Elements.Polygon
Move Bounds data type, class and functions into their own module Bounds
Merge branch 'split_up_geometry_module'
Elements.Polyline: Move makePolyline to Elements.Line module

This function is used by Elements.Polyline and Elements.Polygon and is
of general use.