v1.3.0

• Add d3.geoIdentity for scaling, translating and clipping planar geometry.
• Add d3.geoGraticule10 for conveniently generating a default 10° global graticule.
• Add optional arguments to d3.geoPath for projection and context.
• Deprecate d3.geoClipExtent; use d3.geoIdentity’s clipExtent instead.
• Improve the README.