title: <%= yeoman.app %> and <%=yeoman.dist %> variables for a gruntfile
body: <p>I often see in some example gruntfiles the use of &lt;%= yeoman.app %> and &lt;%= yeoman.dist %> environment variables. I haven't used this myself but where do those variables get derived from?</p>
  
  <p>Also, is it possible to override those variables? Does one need to have yeoman in order to use those particular environment variables?</p>
  
  <p>I've read through the <a href="https://github.com/yeoman/yeoman/wiki">documentation</a> and the <a href="http://yeoman.io/faq.html">FAQ</a>. Are there resources that discusses this more?</p>