I didn't dare to share this but in case... just few days after my message I fall on the inspiring work of Dr. Hans Vandierendonck (presented during the 2nd International Summer School on Advances in Programming Languages in Edinburgh).

Certainly too much, but he open sourced a scheduler (C++11) with interesting ressources and a minimal example of a staged bootstrap. 
It's clearly oriented parallel computing, but the way to declare dependencies and the idea of versionned object is quite good.

All materials are dipsonible here: http://www.macs.hw.ac.uk/~dsg/events/ISS-AiPL-2014/materials/Vandierendonck/