[Outreachy][PATCH 00/10] Finish converting git bisect to C part 2

These patches correspond to a second part of patch series of Outreachy project "Finish converting `git bisect` from shell to C" started by Pranit Bauva and Tanushree Tumane (https://public-inbox.org/git/pull.117.git.gitgitgadget@gmail.com) and continued by me.

This second part depends on mr/bisect-in-c-1 and it is formed by reimplementations of some `git bisect` subcommands and removal of some temporary subcommands.

These patch series emails were generated from: https://gitlab.com/mirucam/git/commits/git-bisect-work-part2.

General changes ---------------

* Rebase on next branch: 5900a2a8f9 (Sync with master, 2020-02-25).
* Improve commit messages.
* Amend patch series titles.
* Reorder commits.

Specific changes ----------------

[1/10] bisect--helper: introduce new `write_in_file()` function

* New patch to refactor code in `write_in_file()` function and use it in
`write_terms()`.

--

[2/10] bisect--helper: reimplement `bisect_next` and `bisect_auto_next` shell functions in C

* Fix `repo_init_revisions()` and bisect_next_all` calls after 
rebase on master.
* Add blank line.
* Remove goto statements in `bisect_skipped_commits()`.
* Add `clear_commit_marks()` in `process_skipped_commits()`.
* Use `write_in_file()` in `bisect_successful()`.
* Change header return type and internal returns to enum in 
`bisect_next()` and `bisect_auto_next()`.
* Improve code comments.

--

[3/10] bisect--helper: finish porting `bisect_start()` to C

* Change header return type and internal returns to enum in `bisect_start()`.
* Improve code comments. 

--

[6/10] bisect--helper: reimplement `bisect_autostart` shell function in C

* Change an internal return to enum in `bisect_autostart()`.

--

[7/10] bisect--helper: reimplement `bisect_state` & `bisect_head` shell functions in C

* Change header return type and internal returns to enum in `bisect_state()`.

--

Miriam Rubio (1):
  bisect--helper: introduce new `write_in_file()` function

Pranit Bauva (9):
  bisect--helper: reimplement `bisect_next` and `bisect_auto_next` shell
    functions in C
  bisect--helper: finish porting `bisect_start()` to C
  bisect--helper: retire `--bisect-clean-state` subcommand
  bisect--helper: retire `--next-all` subcommand
  bisect--helper: reimplement `bisect_autostart` shell function in C
  bisect--helper: reimplement `bisect_state` & `bisect_head` shell
    functions in C
  bisect--helper: retire `--check-expected-revs` subcommand
  bisect--helper: retire `--write-terms` subcommand
  bisect--helper: retire `--bisect-autostart` subcommand

 bisect.c                 |  11 ++
 builtin/bisect--helper.c | 388 ++++++++++++++++++++++++++++++++++-----
 git-bisect.sh            | 145 +--------------
 3 files changed, 358 insertions(+), 186 deletions(-)