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