rebase: restore i18n of a hint message
As noticed by Yuya, I lost the _() call in
71fee4564410 (rebase: use
rewriteutil.precheck() instead of reimplementing it, 2019-12-18).
Differential Revision: https://phab.mercurial-scm.org/D7697
status: make unresolved files always be in the morestatus structured output
We don't know the status of those files, only that they're unresolved, so
we don't output the status for those - any code parsing this will have to be
tolerant to that.
Differential Revision: https://phab.mercurial-scm.org/D7668
status: make morestatus call out unresolved conflicts after update
Differential Revision: https://phab.mercurial-scm.org/D7704
status: extract active-merge state for reuse
Differential Revision: https://phab.mercurial-scm.org/D7667