title: Django filter objects by Many-To-Many field intersection
body: <p>Hello,</p> 
  <p>Can some good person give me advice on how to get a queryset of ordered objects by intersecting a many-to-many field with a given one object's many-to-many field?</p> 
  <p>For example I have:</p>
  <p>class Video(models.Model):<br/>
  tags = models.ManyToManyField(Tag, blank=True)</p>
  <p>...</p>
  </p>class Tag(models.Model):<br/>
     name = models.CharField(max_length=64)</p>
  <p>...</p>
  <p>I select one Video object and would like to have first ten objects that have most similar tags set to show like related videos.</p> 
  <p>Thanks in advance!</p>