* 'js/commit-gpgsign' of ../git-gui:
  git-gui: respect commit.gpgsign again

As of v2.9.0, `git commit-tree` no longer heeds the `commit.gpgsign`
config setting. This broke committing with GPG signature in Git GUI.

This fixes https://github.com/git-for-windows/git/issues/850

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>

A small doc update.

* hv/doc-commit-reference-style:
  SubmittingPatches: use gitk's "Copy commit summary" format
  SubmittingPatches: document how to reference previous commits

A small test clean-up for a topic introduced in v2.9.1 and later.

* sg/reflog-past-root:
  t1410: remove superfluous 'git reflog' from the 'walk past root' test

Small code clean-up.

* rs/mailinfo-lib:
  mailinfo: recycle strbuf in check_header()

Small code and comment clean-up.

* jk/tighten-alloc:
  receive-pack: use FLEX_ALLOC_MEM in queue_command()
  correct FLEXPTR_* example in comment

A small code clean-up.

* rs/use-strbuf-add-unique-abbrev:
  use strbuf_add_unique_abbrev() for adding short hashes

A small code clean-up.

* rs/merge-recursive-string-list-init:
  merge-recursive: use STRING_LIST_INIT_NODUP

A small code clean-up.

* rs/merge-add-strategies-simplification:
  merge: use string_list_split() in add_strategies()