Improve documentation concerning the status.submodulesummary setting

'git status' and 'git commit' can be told to also show the output of "git
submodule summary" by setting the "status.submodulesummary" config option.
But status and commit also honor the "diff.ignoreSubmodules" and the
"submodule.<name>.ignore" settings, which then disable the summary partly
or completely. This - and the fact that the last two settings do not
affect the "git submodule" commands at all - is not well documented.

Extend the documentation in those places where "status.submodulesummary",
"diff.ignoreSubmodules" and "submodule.<name>.ignore" are described to
better explain these dependencies.

Thanks-to: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'bc/submodule-status-ignored' into next

* bc/submodule-status-ignored:
  Improve documentation concerning the status.submodulesummary setting
Merge branch 'nd/push-no-thin'

"git push --no-thin" was a no-op by mistake.

* nd/push-no-thin:
  push: respect --no-thin
Merge branch 'sh/pull-rebase-preserve'

"git pull --rebase" always flattened the history; pull.rebase can
now be set to "preserve" to invoke "rebase --preserve-merges".

* sh/pull-rebase-preserve:
  pull: allow pull to preserve merges when rebasing
Merge branch 'jn/post-receive-utf8'

Update post-receive-email script to make sure the message contents
and pathnames are encoded consistently in UTF-8.

* jn/post-receive-utf8:
  hooks/post-receive-email: set declared encoding to utf-8
  hooks/post-receive-email: force log messages in UTF-8
  hooks/post-receive-email: use plumbing instead of git log/show
Merge branch 'es/rebase-i-respect-core-commentchar'

"rebase -i" forgot that the comment character can be configurable
while reading its insn sheet.

* es/rebase-i-respect-core-commentchar:
  rebase -i: fix cases ignoring core.commentchar
Merge branch 'js/xread-in-full'

A call to xread() was used without a loop around to cope with short
read in the codepath to stream new contents to a pack.

* js/xread-in-full:
  stream_to_pack: xread does not guarantee to read all requested bytes
Merge branch 'sb/mailmap-freeing-NULL-is-ok'

* sb/mailmap-freeing-NULL-is-ok:
  mailmap: remove redundant check for freeing memory
Merge branch 'tf/gitweb-ss-tweak'

Tweak Gitweb CSS to layout some elements better.

* tf/gitweb-ss-tweak:
  gitweb: make search help link less ugly
  gitweb: omit the repository owner when it is unset
  gitweb: vertically centre contents of page footer
  gitweb: ensure OPML text fits inside its box
Merge branch 'rt/rebase-p-no-merge-summary'

"git rebase -p" internally used the merge machinery, but when
rebasing, there should not be a need for merge summary.

* rt/rebase-p-no-merge-summary:
  rebase --preserve-merges: ignore "merge.log" config
Merge branch 'es/rebase-i-no-abbrev'

The commit object names in the insn sheet that was prepared at the
beginning of "rebase -i" session can become ambiguous as the
rebasing progresses and the repository gains more commits. Make
sure the internal record is kept with full 40-hex object names.

* es/rebase-i-no-abbrev:
  rebase -i: fix short SHA-1 collision
  t3404: rebase -i: demonstrate short SHA-1 collision
  t3404: make tests more self-contained
Merge branch 'jc/ls-files-killed-optim'

"git ls-files -k" needs to crawl only the part of the working tree
that may overlap the paths in the index to find killed files, but
shared code with the logic to find all the untracked files, which
made it unnecessarily inefficient.

* jc/ls-files-killed-optim:
  dir.c::test_one_path(): work around directory_exists_in_index_icase() breakage
  t3010: update to demonstrate "ls-files -k" optimization pitfalls
  ls-files -k: a directory only can be killed if the index has a non-directory
  dir.c: use the cache_* macro to access the current index
Update draft release notes to 1.8.5

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'master' into next

* master:
  Update draft release notes to 1.8.5