hadley/dplyr — pull request #723 by matthieugomez (2014-10-24 21:53:07+00:00)
Title: data.table: inplace option + group_by does not reorder data.table

- inplace option re-implemented for mutate, mutate_each
- inplace option created for arrange using setorder(na.last=TRUE)
- inplace option created for group_by
- group_by does not reorder a data.table anymore. I just remove the setkeyv line since I don't think it's required by anything.