hadley/dplyr — pull request #748 by matthieugomez (2014-11-05 16:05:11+00:00)
Title: add r() and w() to select_vars

These functions are less explicit than the current one allowed in `select_vars`, but quicker to type.
`w()` allows to use wildcards.
`r()` is another name for the function matches.

```R
select_vars(c("id", "id2", "other"), w("id*"))
id id2
"id" "id2"
select_vars(c("id", "id2", "other"), r("^id"))
id id2
"id" "id2"
```