mongoid/mongoid — pull request #3526 by kareemk (2014-02-09 18:14:34+00:00)
Title: Callbacks are fired multipled times for nested embedded_many relationships

I tried to fix this but hit a wall. The closes I got was:

```ruby
--- a/lib/mongoid/callbacks.rb
+++ b/lib/mongoid/callbacks.rb
@@ -169,7 +169,6 @@ module Mongoid
Array.wrap(relation).each do |child|
next if children.include?(child)
children.add(child) if cascadable_child?(kind, child)
- child.send(:cascadable_children, kind, children)
end
end
end
```

but this causes `spec/mongoid/nested_attributes_spec.rb:709` to fail