* jk/completion-diff-submodule:
  completion: add completion for --submodule=* diff option

"git format-patch" learned format.from configuration variable to
specify the default settings for its "--from" option.

* jt/format-patch-from-config:
  format-patch: format.from gives the default for --from

Teach git-completion.bash to complete --submodule= for git commands
which take diff options. Also teach completion for git-log to support
--diff-algorithms as well.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* cp/completion-clone-recurse-submodules:
  completion: add option '--recurse-submodules' to 'git clone'

Style fixes for "git subtree" (in contrib/).

* da/subtree-modernize:
  subtree: adjust function definitions to match CodingGuidelines
  subtree: adjust style to match CodingGuidelines

"git jump" script (in contrib/) has been updated a bit.

* jk/git-jump:
  contrib/git-jump: fix typo in README
  contrib/git-jump: add whitespace-checking mode
  contrib/git-jump: fix greedy regex when matching hunks

The build procedure for "git persistent-https" helper (in contrib/)
has been updated so that it can be built with more recent versions
of Go.

* pm/build-persistent-https-with-recent-go:
  contrib/persistent-https: use Git version for build label
  contrib/persistent-https: update ldflags syntax for Go 1.7+

"git merge" in Git v2.9 was taught to forbid merging an unrelated
lines of history by default, but that is exactly the kind of thing
the "--rejoin" mode of "git subtree" (in contrib/) wants to do.
"git subtree" has been taught to use the "--allow-unrelated-histories"
option to override the default.

* da/subtree-2.9-regression:
  subtree: fix "git subtree split --rejoin"
  t7900-subtree.sh: fix quoting and broken && chains

This helps users who would prefer format-patch to default to --from,
and makes it easier to change the default in the future.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

"git worktree prune" protected worktrees that are marked as
"locked" by creating a file in a known location.  "git worktree"
command learned a dedicated command pair to create and remove such
a file, so that the users do not have to do this with editor.

* nd/worktree-lock:
  worktree.c: find_worktree() search by path suffix
  worktree: add "unlock" command
  worktree: add "lock" command
  worktree.c: add is_worktree_locked()
  worktree.c: add is_main_worktree()
  worktree.c: add find_worktree()