hadley/ggplot2 — pull request #922 by jiho (2014-02-27 16:42:24+00:00)
Title: Quick approximation for map projections

Instead of reprojecting everything, we just set the aspect ratio of the plot
to the ratio between the length of one degree of lat over one degree of lon.

Edit on 2014-02-27: rebased on head + latest version of roxygen