[PATCH v2 00/12] fix checking out a being-rebased branch

Much happier with this version. This makes

 - git checkout refuse if a branch is under rebase or bisect
   elsewhere

 - git worktree add refuse if a branch is under rebase or bisect

 - git branch -D refuse if a branch is under rebase or bisect.
   This applies for single worktree case as well.

 - git branch -M refuse if a branch is under rebase or bisect
   (single worktree case as well)

  [01/12] path.c: add git_common_path() and strbuf_git_common_path()
  [02/12] worktree.c: store "id" instead of "git_dir"
  [03/12] worktree.c: make find_shared_symref() return struct worktree *
  [04/12] worktree.c: mark current worktree
  [05/12] path.c: refactor and add worktree_git_path()
  [06/12] wt-status.c: split rebase detection out of wt_status_get_state()
  [07/12] wt-status.c: make wt_status_check_rebase() work on any worktree
  [08/12] worktree.c: avoid referencing to worktrees[i] multiple times
  [09/12] worktree.c: test if branch being rebased in another worktree
  [10/12] wt-status.c: split bisect detection out of wt_status_get_state()
  [11/12] worktree.c: test if branch being bisected in another worktree
  [12/12] branch: do not rename a branch under bisect or rebase

Total 13 files changed, 335 insertions(+), 67 deletions(-)