hadley/dplyr — pull request #190 by eddelbuettel (2014-01-20 14:58:36+00:00)
Title: protect a few examples with if(require) 

Now examples run in `R CMD check` for me -- but I didn't uninstall some I have here (eg RPostgreSQL, RSQLite, knitr). It is not perfect, but it kicks the can a little down the road.