Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Fri, 10 Mar 2017 10:36:46 -0800] rev 2083
discovery: introduce a official 'obshash associated to a range
The hash in a combination of the hash a its subrange. If the range is a leaf,
we have the obsmarker relevant to the node in that leaf range.