This changes the default behavior of the function to check only stdout
for interactivity, but for most cases this should be what we want.
* lisp/eshell/esh-io.el (eshell-interactive-output-p): Pass HANDLES
and handle INDEX.
* lisp/eshell/em-term.el (eshell-visual-command-p): Check for
interactivity of both stdout and stderr.