plt/racket — pull request #421 by khinsen (2013-09-02 14:23:36+00:00)
Title: Simplified browser configuration for MacOS X

Add an optional #:browser argument to send-url/mac and export it.

This makes it straightforward to use different browsers and/or to
configure a different one:

```racket
(require net/sendurl)
(external-browser (lambda (url) (send-url/mac url #:browser "Conkeror")))
```