Merge branch 'mr/bisect-in-c-2'

Rewrite of the "git bisect" script in C continues. * mr/bisect-in-c-2: bisect--helper: reimplement `bisect_next` and `bisect_auto_next` shell functions in C bisect: call 'clear_commit_marks_all()' in 'bisect_next_all()' bisect--helper: reimplement `bisect_autostart` shell function in C bisect--helper: introduce new `write_in_file()` function bisect--helper: use '-res' in 'cmd_bisect__helper' return bisect--helper: BUG() in cmd_*() on invalid subcommand