test-compat: merge stable into mercurial-4.3

test: backed out test change from changeset a18ca224e812 The related mercurial changeset, ad5f2b923b0d, is not in the stable branch yet.

test: backed out output change from 85ab7d2d9fd6 Mercurial core default branch does not have the related changeset yet (a7e49a5b3e6f).

branching: merge with stable

obsnote: warn if user try to store a note in obsmarker on an older hg Support to store a note in obsmarker is from hg>=4.4. We have added notes support to all the evolve commands but we do support versions which don't support storing note in obsmarker. Warn if user tries to store a note in older hg.

topic: use 'hookargs' over 'tr.changes' for flow control The 'tr.changes' attribute do not exists until 4.2.

topic: move function wrapping from reposetup to uisetup Having the function un reposetup means they get wrapped over and over again for long lived process.

test: publish the root of the repo in flow reject-untopiced The lack of default branch confuses older version

genericcaches: handle the lack of util.timer in 4.1 We do the same trick as usual.

topics: fix `hg stack` in case of split This patch fixes the behaviour of hg stack which throws an error in some cases when there are multiple successors. The case of divergence is not handled yet.