json4s/json4s — pull request #86 by thetrav (2013-12-30 03:31:14+00:00)
Title: Mark a change in value type as a change rather than an add and a remove

Previously the result of the new spec I've added was:
Diff(JNothing, JObject("a" -> "different"), JObject("a" -> 1))

A change of type is a change, not a removal and an addition