Move hflights to suggests
Start explaining notes for cran submission
Reduce example execution time
avoid copy in grouped_df
initial dfloc
Merge branch 'master' of https://github.com/hadley/dplyr
Don't use in-place assignment b/c it forces copy.
Closes #171
Eliminate redundant wrap function
Work around weird knitr bug
Merge branch 'master' into v0.2