title: Date Range List filter for foreign key Django admin
body: <p>I have a model like this</p>
  
  <pre><code>class BaseRequest(models.Model):
      created = models.DateTimeField(auto_now_add=True, editable=False)
      modified = models.DateTimeField(auto_now=True, editable=False)   
      price_quoted =  models.DecimalField(max_digits=10, decimal_places=2,null=True, blank=True)
  
   class RequestLeg(models.Model):
      created = models.DateTimeField(auto_now_add=True, editable=False)
      modified = models.DateTimeField(auto_now=True, editable=False)
      depart_date = models.DateField()
      num_seats = models.IntegerField()
  
  class Request(BaseRequest):
      owner = models.ForeignKey(User, null=True, blank=True)
      name = models.CharField(max_length=30, null=True, blank=True)
      email = models.EmailField()
      phone = models.CharField(max_length=30, null=True, blank=True)
      legs = models.ManyToManyField(RequestLeg)
  </code></pre>
  
  <p>and admin for above Request model is </p>
  
  <pre><code>class RequestAdmin(NoDeletionsAdmin):
      list_display=['id', 'created', 'name', 'depart_date']
  
      def depart_date(self, obj):
          try:
              return min([leg.depart_date for leg in obj.legs.all()])
          except ValueError, e:
              return None
  </code></pre>
  
  <p>I want Daterangelist filter for depart_date in RequestAdmin ?
  <img src="https://i.stack.imgur.com/lMns7.png" alt="enter image description here"></p>