Cannot list untracked changes stashed with the --include-untracked flag

Hi,

After stashing changes using `git stash save --include-untracked` you
can not see new files when listing the stash using `git stash list
--numstat`
There is no flag to allow such behavior.

This discussion started at: https://github.com/FredrikNoren/ungit/issues/1459

Thanks,
Gil Tichon.