title: django filter by manytomany or no record
body: <p>I have models</p>
  
  <pre><code>class Product(models.Model):
      title = models.CharField(...)
  
  class PropertyType(models.Model):
      title = models.CharField(...)
  
  class Property(models.Model):
      property_type = models.ForeignKey(PropertyType)
      product = models.ForeignKey(Product, related_name='properties')
      value = models.CharField(...)
  </code></pre>
  
  <p>So, how can i filter Products for properties with some value and property_type and include products, which have no property with same property_type</p>
  
  <p>Something like this</p>
  
  <pre><code>properties = Property.objects.filter(property_type__pk=12, value='anyValue')
  products = Product.objects.filter(Q(properties__in=properties)|
                Q(NO PROPERTY RECORD WITH PROPERTYTYPE__ID=12 FOR PRODUCT))
  </code></pre>