amerine/acts_as_tree — pull request #25 by dv (2014-05-16 12:32:36+00:00)
Title: Set counter_cache column by default to "children_count"

Not sure if this is required for all Rails - if I don't, Rails tries to update the "_count" column of the parent when destroying a child instead of the "children_count", which it can't find and it subsequently throws an error.