Zoom SVG World Map with D3 - Version 4

World map includes a path for each country. Zoom the map using D3, Version 4. Provides Mouse Wheel zoom. Uses d3.zoom() (d3 v.4). Includes smoothing transtions. Best svg zoom behavior at this time. D3,Version 4 has finally corrected the problem with FF.
(World map SVG file available at: www.svgDiscovery.com/B0/world.svg)

SVG File: Country Borders and Names
Javascript: