title: Rails: URL helper to combine URL params?
body: <p>How would I either create a helper or use the built-in <code>link_to</code> helper to combine URL params?</p>
  
  <p>For instance, say I'm on a page with the URL parameter of <code>status</code>:</p>
  
  <p><code>http://example.com/items?status=new</code></p>
  
  <p>I have another link for carriers that I'd basically want to append to that, like so:</p>
  
  <p><code>http://example.com/items?status=new&amp;carrier=fedex</code></p>
  
  <p>So basically the helper would detect if there were any params in the URL and then append the param to that.</p>