bisect: use standard one-line commit summary This makes bisect use the standardized support for one-line commit summary I added a while back. That means that it will respect the `command-templates.oneline-summary` config. If also means that the default output now includes the first line of the commit message (see test impact). Differential Revision: https://phab.mercurial-scm.org/D10245

rhg: Add more conversions between error types This allows using the `?` operator in more places, as the next commit does. Differential Revision: https://phab.mercurial-scm.org/D10238

tests: resort to fix test with newer git versions Differential Revision: https://phab.mercurial-scm.org/D10242

git: fix missing case from 6266d19556ad (introduction of nodeconstants) Differential Revision: https://phab.mercurial-scm.org/D10241