title: Is is possible to have the Django slugfield unique per user or other model
body: <p>I am setting up a site that has 'pages' that are always within a parent 'category'. Some pages will have the same title but will reside in a different category. Currently django sluggify always adds numbers to the slugs if the name would be the same:</p>
  
  <pre><code> foo/help/
   bar/help-1/
  </code></pre>
  
  <p>Is there a way to get it to output a more intelligent slug so that the slug is unique for the page within the category.</p>
  
  <pre><code>foo/help/
  bar/help/
  etc/help/
  etc/help-1/
  </code></pre>
  
  <p>I am also thinking of having some pages that are unique for a user in the same way. They would always be accessed as a sub of the user making them unique in that way</p>