[src/netbsd-8]: src/bin/sh Pull up following revision(s) (requested by kre in...

[snj <snj%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2b070ae30bef
branches:  netbsd-8
changeset: 434201:2b070ae30bef
user:      snj <snj%NetBSD.org@localhost>
date:      Wed Aug 09 05:35:18 2017 +0000

description:
Pull up following revision(s) (requested by kre in ticket #199):
        bin/sh/input.c: revision 1.61
        bin/sh/parser.c: revision 1.143
PR bin/52458
Avoid mangling history when editing is enabled, and the prompt contains a \n
Also, allow empty input lines into history when they are being appended to
a previous (partial) command (but not when they would just make an empty entry)