hadley/ggplot2 — pull request #456 by wch (2012-03-27 02:19:18+00:00)
Title: Fix and clean up dodging code

This fixes and cleans up the code for dodging by groups. It fixes #436 and a dodging bug mentioned in this thread:
http://groups.google.com/group/ggplot2/browse_thread/thread/e6086175832049c1