Stop post-processing branchmap entries for obsolescence
With the Mercurial 6.1 core taking obsolescence into account while updating branchmap, it is no longer necessary to perform the (very slow) post-processing provided by the evolve extension.
Because of the big jump in minimum required Mercurial version, we make it a major version change.
See also heptapod#633 (closed) and heptapod#632 (closed)
Edited by Georges Racinet