Older versions of meld listed --output in `meld --help`.
Newer versions only mention `meld [OPTIONS...]`.
Improve the checks to catch these newer versions.

Add a `mergetool.meld.hasOutput` configuration to allow
overriding the heuristic.

Reported-by: Andrey Novoseltsev <novoselt@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* maint-2.0:
  git-tag.txt: Add a missing hyphen to `-s`

* maint-1.9:
  git-tag.txt: Add a missing hyphen to `-s`

* maint-1.8.5:
  git-tag.txt: Add a missing hyphen to `-s`

Some MUAs mangled a line in a message that begins with "From " to
">From " when writing to a mailbox file and feeding such an input to
"git am" used to lose such a line.

* jk/mbox-from-line:
  mailinfo: work around -Wstring-plus-int warning
  mailinfo: make ">From" in-body header check more robust

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

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

"git fsck" failed to report that it found corrupt objects via its
exit status in some cases.

* jk/fsck-exit-code-fix:
  fsck: return non-zero status on missing ref tips
  fsck: exit with non-zero status upon error from fsck_obj()

"git config --add section.var val" used to lose existing
section.var whose value was an empty string.

* ta/config-add-to-empty-or-true-fix:
  config: avoid a funny sentinel value "a^"
  make config --add behave correctly for empty and NULL values

Reachability check (used in "git prune" and friends) did not add a
detached HEAD as a starting point to traverse objects still in use.

* mk/reachable-protect-detached-head:
  reachable.c: add HEAD to reachability starting commits