Merge changes from upstream libedit.

Our libedit has been diverging from the mainstream version
maintained in NetBSD. As a consequence it has been difficult
to do an appropriate MFV and we have been bringing only
partial updates.

Here we update most of the files to at least match the
version available in NetBSD's snapshot of 20091228. This
version was chosen because it still doesn't include wide
character support (UTF-8), which involves many changes and
new files.

From NetBSD's logs:

Dec 15 22:13:33 2006 - editline.3 el.c el.h histedit.h
add EL_GETFP, and EL_SETFP.

Apr 5 15:53:28 2008 - editline.3 el.c histedit.h readline.c
add EL_REFRESH for the benefit of readline

Sep 10 15:45:37 2008 - common.c el.c read.c refresh.c sig.c term.c term.h tty.c
Allow a single process to control multiple ttys (for pthreads using _REENTRANT)
using multiple EditLine objects.

Jan 18 12:17:24 2009 - el.c read.c readline.c
fix -Wsign-compare issues

Feb 6 14:40:32 2009 - history.c
Plug memory leak, from MySQL.

Feb 5 19:15:44 2009 - histedit.h read.c
match documentation in el_push

Feb 6 13:14:37 2009 - vi.c
Portability fix.

Feb 12 13:39:49 2009 - readline.c term.c
More fixes for existing portability stuff.

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

Feb 15 21:25:01 2009 - sig.c sig.h
in order for read() to return EINTR we need to use sigaction, not signal,
otherwise SA_RESTART is set.

Feb 15 21:55:23 2009 - chared.c chared.h common.c emacs.c filecomplete.c
filecomplete.h key.c key.h read.c readline.c refresh.c search.c
term.c tokenizer.c tty.c vi.c
pass lint on _LP64.

Feb 17 21:34:26 2009 - el.c histedit.h	prompt.c prompt.h
allow for a prompt argument.

Feb 18 15:04:40 2009 - sig.c
SA_RESTART for all signals but SIGINT. From Anon Ymous.

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

Feb 21 23:31:56 2009 - key.c key.h readline.c vi.c
more size_t stuff.

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.

Mar 31 17:38:27 2009 - editline.3 el.c histedit.h prompt.c prompt.h
refresh.c term.c term.h
Implement literal prompt sequences. Now someone can implement
RL_PROMPT_START_LITERAL/RL_PROMPT_END_LITERAL :-)

Mar 31 21:33:17 2009 - term.c
cast to size_t to avoid sign / unsigned comparison warning.

Apr 23 02:03 2009 - term.c
Apply patch (requested by msaitoh in ticket #2007):
Coverity CID 1668: Plug memory leak when malloc() failed.:55 2009

May 11 18:33:30 2009 - editline.3 el.c histedit.h
restore binary compatibility by providing new prompt functions that take
an extra literal character.

May 19 21:45:14 2009 - refresh.c
always scroll when we advance past bottom. From Caleb Welton
cwelton at greenplum dot com.

Jul 17 12:27:57 2009 - term.c
- off by one in the term.h case.
- make code more similar to tcsh (if we want to handle wide chars, this is
  needed; for now it is a no-op)

Jul 22 15:56:29 2009 - el.c
Move filename to the scope it is being used.
From Michael Cook mcook at bbn dot com

Jul 22 15:57:00 2009 - read.c
Always initialize nread since it is an out param.
From Michael Cook mcook at bbn dot com

Jul 22 18:25:26 2009 - el.c
Only need path if we have issetugid... From Anon Ymous

Jul 25 21:19:23 2009 - el.c
Ignore comment lines in .editrc from Jess Thrysoee

Sep 7 21:24:33 2009
histedit.h history.c readline.c
apply apple patches from:
http://opensource.apple.com/source/libedit/libedit-11/patches/

Dec 28 21:52:43 2009 - refresh.c
Fix bug where tab completion on the second or > line that caused listing
ended up corrupting the display by an extra space in the beginning. Reported
by Mac Chan.

Dec 28 22:15:36 2009 - refresh.c term.c
reduce diff with tcsh

Obtained from:	NetBSD
Tested by:	bapt, jilles and current@
MFC after:	1 week