Where did "Free unused nodes" checkbox go? Recently run into some memory lack while I was composing and remembered about this option. Unfortunately, it is not present in Blender since 2.77 release. Was it implemented by default in modern builds or gone away forever?
It was removed because, according to Sergey Sharybin:


  It was basically doing nothing, for ages.


I presume he means that it wasn't having much of an effect as opposed to people not using it.