[PATCH 00/25] worktree lock, move, remove and unlock

This is basically a resend from last time, which happened during rc time. It adds 4 more commands, basically cleaning up the "TODO" list in git-worktree.txt.

So far I've only actually used move and remove (and maybe unlock once because worktree-add failed on me and I had to unlock it manually). And I don't get to move worktrees a lot either so not really extensive testing.

  [01/25] usage.c: move format processing out of die_errno()
  [02/25] usage.c: add sys_error() that prints strerror() automatically
  [03/25] copy.c: import copy_file() from busybox
  [04/25] copy.c: delete unused code in copy_file()
  [05/25] copy.c: convert bb_(p)error_msg to (sys_)error
  [06/25] copy.c: style fix
  [07/25] copy.c: convert copy_file() to copy_dir_recursively()
  [08/25] completion: support git-worktree
  [09/25] git-worktree.txt: keep subcommand listing in alphabetical order
  [10/25] path.c: add git_common_path() and strbuf_git_common_path()
  [11/25] worktree.c: use is_dot_or_dotdot()
  [12/25] worktree.c: store "id" instead of "git_dir"
  [13/25] worktree.c: add clear_worktree()
  [14/25] worktree.c: add find_worktree_by_path()
  [15/25] worktree.c: add is_main_worktree()
  [16/25] worktree.c: add validate_worktree()
  [17/25] worktree.c: add update_worktree_location()
  [18/25] worktree.c: add is_worktree_locked()
  [19/25] worktree: avoid 0{40}, too many zeroes, hard to read
  [20/25] worktree: simplify prefixing paths
  [21/25] worktree: add "lock" command
  [22/25] worktree: add "unlock" command
  [23/25] worktree: add "move" commmand
  [24/25] worktree move: accept destination as directory
  [25/25] worktree: add "remove" command

Total 11 files changed, 1028 insertions(+), 48 deletions(-)