MFC r238173:

MFC	r238173:

Fix issue resizing bin/sh

This partially reverts some changes from r237448 that are causing
breakage when resizing under bin/sh .

Reverted changes from NetBSD are:

Mar 10 20:46:15 2009 - editline.3 read.c
make el_gets set the count to -1 on error to distinguish between EOF and
error.

Feb 19 15:20:22 2009 - read.c sig.c sig.h
reset and redraw on sigcont. From Anon Ymous.

Feb 15 21:24:13 2009
don't restart on EINTR, instead return NULL immediately. From Anon Ymous

PR:		169603
Reported by:	Peter Jeremy, David Shao
MFC after:	3 days
Approved by:	re

git-svn-id: svn://svn.freebsd.org/base/stable/9@238286 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f