CleverRaven/Cataclysm-DDA — pull request #4039 by StraySilverFox (2013-11-01 18:43:16+00:00)
Title: Sleep now intensifies recovery based on time spent sleeping. [CR]

https://github.com/CleverRaven/Cataclysm-DDA/issues/3627

I didn't solve this issue of endless fatigue, but recovery acceleration during extended was simple enough. It needs testing for balance.