title: Ruby on Rails 3.1 without execjs?
body: <p>If you install Ruby on Rails 3.1 the gem <a href="http://rubygems.org/gems/execjs" rel="noreferrer">execjs</a> gets installed by default. I excluded <a href="http://en.wikipedia.org/wiki/CoffeeScript" rel="noreferrer">CoffeeScript</a>, because I thought it needed execjs, but execjs wants to be installed anyway.
  Is execjs now a requirement for Ruby on Rails applications or is there a way to exclude this gem from an installation?</p>