Merge branch 'es/worktree-chatty-to-stderr'

Merge branch 'es/worktree-chatty-to-stderr'

"git worktree add" showed "Preparing worktree" message to the
standard output stream, but when it failed, the message from die()
went to the standard error stream.  Depending on the order the
stdio streams are flushed at the program end, this resulted in
confusing output.  It has been corrected by sending all the chatty
messages to the standard error stream.

* es/worktree-chatty-to-stderr:
  git-worktree.txt: add missing `-v` to synopsis for `worktree list`
  worktree: send "chatty" messages to stderr