added stat_ellipse
committing just the stat_ellipse changes
Not necessary to declare ggplot2:::Stat
added a euclidian distance option
git cruft
Merge pull request #1 from hadley/master

merging updates
merging master
re-building documentation, passing R CMD check
cleaning up style
rolling back .Rbuildignore to 3aeaa1f
fixed up indentation, included reference to car package.
forgot to re-build & document
pulled calculation out into separate function
updated NEWS
Merge pull request #926 from JoFrhwld/feature/stat-ellipse

Feature/stat ellipse