Add d3.geo.projection

Downloaded from http://d3js.org/d3.geo.projection.v0.min.js.

Inferred version by checking the project's Github release page: https://github.com/d3/d3-geo-projection/releases.

Popularity: Has 94 stars, is part of the very popular (24k star) d3 project, and is a dependency of the 1k star https://github.com/wrobstory/vincent.