merge with stable

test: fix output of test-discovery-obshashrange.t The username is now quoted in the output.

obscache: use _readmarkers() from core with correct signature The copied _readmarkers() went stale with Mercurial core commit 5d3ba4395288 (obsstore: let read marker API take a range of offsets, 2017-06-04). At the same time, the Mercurial core version of the function gained the desired offset argument, so we can now use that function.

topics: take locks and start transaction before calling _changetopics This will help us in calling _changetopics in other transactions which already started. Currently the _changetopics creates its own transaction and hence can't be used it a same transaction with any other function or logic.

compat: fix instabilities compat We added an instabilities method for old version of Mercurial. But we returned an old value for orphan changesets, the one before the big evolve renaming. Fix the return value to match the new return values.

test: fix output of test-discovery-obshashrange.t The username is now quoted in the output.

revset: bumped volatile set was deprecated Use phasedivergent volatile set instead. Match 07a76d4f2297 mercurial changeset.

revset: divergent volatile set was deprecated Use contentdivergent volatile set instead. Match 31c922423f3f mercurial changeset.

revset: unstable volatile set was deprecated Use orphan volatile set instead. Match 5579864798c6 mercurial changeset.

revset: bumped() is deprecated Use phasedivergent() instead. Match bd71c06eb62f mercurial changeset.