vis: fix I/O redirection bugs, cleanup vis_pipe

The `:!` command did redirect stdout to a pipe which was used by
`vis-menu` to return the selected entry. However, this breaks
other interactive commands such as `:!/bin/sh` where command
output was never displayed. Instead we modified `vis-menu` to
re-open /dev/tty for its user interface which makes it work
as a regular filter `:|`

This patch also obsoletes the interactive flag previously passed
to the vis_pipe function. Interactive mode is instead enabled
by piping an invalid range.

0 files changed, 0 insertions, 0 deletions