prune: move help about biject after the one about split and fold The --biject flag seems a less common use case.

prune: no longer consider dropping --biject Field testing show it save people one wrong call often enough that it is worth keeping.

prune: more human-friendly documentation for --biject

prune: use ``-s/--succ`` in documentation Extracted by Pierre-Yves David

branching: merge with stable

compat: import the module dagutil module in evolve Discovery code is core have been rewritten to no longer depends on dagutil and the module have been removed. This break evolve's obsmarker discovery (older version of the discovery use the same concept).. A quick work around is to import the dagutil module in evolve and use that for now.

evolve: delete evolvestate after aborting interrupted `next --evolve` We didn't use to delete the evolvestate after aborting an interrupted `next --evolve`. This patch makes sure we do that. The test changes demonstrate the fix and we add a CHANGELOG entry about the fix.

tests: check that we delete evolvestate correctly after abort/stop This patch adds test to check whether we delete the evolvestate correctly after aborting or stopping an interrupted evolve which is caused because of `next --evolve`.

changelog: update with issue5927 fix

evolve: set the second parent if we get conflicts while evolving This patch makes sure we set the second parent correctly if we run into conflicts while evolving. Also, we need to make sure to reset to one parent before committing.