git-new-workdir: Don't fail if the target directory is empty

Allow new workdirs to be created in an empty directory (similar to "git
clone").  Provide more error checking and clean up on failure.

Signed-off-by: Paul Smith <paul@mad-scientist.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'cc/interpret-trailers'

Small fixes to a new experimental command already in 'master'.

* cc/interpret-trailers:
  trailer: display a trailer without its trailing newline
  trailer: ignore comment lines inside the trailers
Merge branch 'tb/no-relative-file-url'

* tb/no-relative-file-url:
  t5705: the file:// URL should be absolute
Merge branch 'mh/doc-remote-helper-xref'

* mh/doc-remote-helper-xref:
  doc: add some crossrefs between manual pages
Merge branch 'sn/tutorial-status-output-example'

* sn/tutorial-status-output-example:
  gittutorial: fix output of 'git status'
Merge branch 'sv/submitting-final-patch'

* sv/submitting-final-patch:
  SubmittingPatches: final submission is To: maintainer and CC: list
Merge branch 'jc/clone-borrow' into jch

Allow "git clone --reference" to be used more safely.

* jc/clone-borrow:
  clone: --dissociate option to mark that reference is only temporary
Merge branch 'jc/checkout-local-track-report' into jch

The report from "git checkout" on a branch that builds on another
local branch by setting its branch.*.merge to branch name (not a
full refname) incorrectly said that the upstream is gone.

* jc/checkout-local-track-report:
  checkout: report upstream correctly even with loosely defined branch.*.merge
Merge branch 'jc/diff-b-m' into jch

Fix long-standing bug in "diff -B -M" output.

* jc/diff-b-m:
  diff -B -M: fix output for "copy and then rewrite" case
Merge branch 'jc/strbuf-add-lines-avoid-sp-ht-sequence' into jch

The commented output used to blindly add a SP before the payload
line, resulting in "# \t<indented text>\n" when the payload began
with a HT.  Instead, produce "#\t<indented text>\n".

* jc/strbuf-add-lines-avoid-sp-ht-sequence:
  strbuf_add_commented_lines(): avoid SP-HT sequence in commented lines
Merge branch 'jc/conflict-hint' into jch

Unlike all the other hints given in the commit log editor, the list
of conflicted paths were appended at the end without commented out.

* jc/conflict-hint:
  merge & sequencer: turn "Conflicts:" hint into a comment
  builtin/commit.c: extract ignore_non_trailer() helper function
  merge & sequencer: unify codepaths that write "Conflicts:" hint
  builtin/merge.c: drop a parameter that is never used
Merge branch 'nd/lockfile-absolute' into jch

The lockfile API can get confused which file to clean up when the
process moved the $cwd after creating a lockfile.

* nd/lockfile-absolute:
  lockfile.c: store absolute path
Merge branch 'jc/merge-bases' into jch

* jc/merge-bases:
  get_merge_bases(): always clean-up object flags
  bisect: clean flags after checking merge bases
Merge branch 'br/imap-send-verbosity' into jch

* br/imap-send-verbosity:
  imap-send: use parse options API to determine verbosity
Merge branch 'br/imap-send-via-libcurl' into jch

* br/imap-send-via-libcurl:
  git-imap-send: use libcurl for implementation
Merge branch 'rs/env-array-in-child-process' into jch

* rs/env-array-in-child-process:
  use args member of struct child_process
Merge branch 'tq/git-ssh-command' into jch

Allow passing extra set of arguments when ssh is invoked to create
an encrypted & authenticated connection, which is not possible with
existing GIT_SSH mechanism, which was designed more to match what
other programs with similar variables did, not necessarily to be
more useful.

* tq/git-ssh-command:
  git_connect: set ssh shell command in GIT_SSH_COMMAND
Merge branch 'jk/checkout-from-tree' into jch

* jk/checkout-from-tree:
  checkout $tree: do not throw away unchanged index entries
Merge branch 'mb/enable-lib-terminal-test-on-newer-darwin' into jch

We probably should drop this, though. ($gmane/259609).

* mb/enable-lib-terminal-test-on-newer-darwin:
  t/lib-terminal: allow TTY tests to run under recent Mac OS
Merge branch 'sv/get-builtin' into jch

* sv/get-builtin:
  builtin: move builtin retrieval to get_builtin()