prune: wrap mercurial internal to add parent information in prune marker We store as a p1 (and p2) key in the extra dict for marker. This allow us to record this information for future use without requiering a format change.

evolve: drop `latercomer` and `conflicting` compatibility. Those old alias are deprecated for a long time now. All computations related to troubles are in Mercurial core for multiple versions.

test: get rid of all reference to conflicting changesets They are now called divergent for a long time.