Log Message:
less: Update to 643

pkgsrc changes:
 - Remove patch-line.c: was a backport from upstream, no longer needed
 - Add patch-edit.c because several <signal.h> definitions are actually
   accessed on non-OS2 codepaths as well (noticed on NetBSD but should be
   relevant for all non-OS2 platforms)

Changes:
Major changes between "less" versions 633 and 643

* Fix problem when a program piping into less reads from the tty,
  like sudo asking for password (github #368).
* Fix search modifier ^E after ^W.
* Fix bug using negated (^N) search (github #374).
* Fix erroneous EOF when terminal window size changes (github #372).
* Fix compile error with some definitions of ECHONL (github #395).
* Fix regression in exit code when stdin is /dev/null and
  output is a file (github #373).
* Add lesstest test suite to production release (github #344).
* Change lesstest output to conform with
  automake Simple Test Format (github #399).

Major changes between "less" versions 632 and 633

* Fix build on systems which have ncurses/termcap.h or
  ncursesw/termcap.h but not termcap.h.

Major changes between "less" versions 608 and 632

* Add LESSUTFCHARDEF environment variable (github #275).
* Add # command (github #330).
* Add ^S search modifier (github #196).
* Add --wordwrap option (github #113).
* Add --no-vbell option (github #304).
* Add --no-search-headers option (github #44).
* Add --modelines option (github #89).
* Add --intr option (github #224).
* Add --proc-backspace, --proc-tab and --proc-return options (github #335).
* Add --show-preproc-errors option (github #258).
* Add LESS_LINES and LESS_COLUMNS environment variables (github #84).
* Add LESS_DATA_DELAY environment variable (github #337).
* Allow empty "lines" field in --header option.
* Update Unicode tables.
* Improve ability of ^X to interrupt F command (github #49).
* Status column (-J) shows off-screen matches.
* Parenthesized sub-patterns in searches are colored with unique colors,
  if supported by the regular expression library (github #196).
* Don't allow opening a tty as file input unless -f is set (github #309).
* Don't require newline input after +&... option (github #339).
* Fix incorrect handling of some Private Use Unicode characters.
* Fix ANSI color bug when overstriking with colored chars (github #276).
* Fix compiler const warning (github #279).
* Fix signal race in iread (github #280).
* Fix reading procfs files on Linux (github #282).
* Fix --ignore-case with ctrl-R (no regex) search (github #300).
* Fix bug doing repeat search after setting & filter (github #299).
* Fix bug doing repeat search before non-repeat search.
* Fix crash with -R and certain line lengths (github #338).
* Don't retain search options from a cancelled search (github #302).
* Don't call realpath on fake filenames like "-" (github #289).
* Implement lesstest test suite.
* Convert function parameter definitions from K&R to C89 (github #316).