As a convenience, when <branch> is omitted from "git worktree <path>
<branch>" and neither -b nor -B is used, automatically create a new
branch named after <path>, as if "-b $(basename <path>)" was specified.
Thus, "git worktree add ../hotfix" creates a new branch named "hotfix"
and associates it with new worktree "../hotfix".
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>