Implements tab completion and history.

It contains the linenoise library.

Adds the raidautorun builtin command.

To support using sash as a #! interpreter.

Fix the line marking command in the builtin ed command.

Fix the where builtin command when used with empty $PATH entries.

To fix a buffer overflow with a very long command line.

I am confident that nobody needs to start sash from a window manager
menu.

Closes: #1073672

That version is many releases in the past.

This directory has not been created anymore in a very long time.

sash 3.7-8, released in 2008, stopped creating this user.
At this point we can be reasonably sure that it is not around anymore
even on upgraded systems.