2016/08/28
+ improve parsing and trace for "bindkey", to convert space to/from
"\s", as well as handle octal escapes for single byte characters.
+ change explicit checks for space character used for select or toggle
to make this rebindable to "TOGGLE" (prompted by discussion with
Paul van Tilburg).
+ add default bindings for cursor left/right to formbox. The cursor
left/right cases were replaced with rebindable symbols in 2005/12/07
without providing these keys as default values (report/patch by
Miroslav Lichvar).
+ modified autoconf macros
+ CF_PROG_LINT add cpplint to programs to use; drop ad hoc tdlint and
alint.
+ CF_CC_ENV_FLAGS don't limit the check to -I, -U and -D options,
since the added options can include various compiler options before
and after preprocessor options.
+ CF_GNU_SOURCE recent glibc (Debian 2.23-4 for example) has
misordered ifdef/checks for new symbol _DEFAULT_SOURCE, producing
warning messages when only _GNU_SOURCE is defined. Add a followup
check to define _DEFAULT_SOURCE.
+ CF_XOPEN_SOURCE use _GNU_SOURCE for cygwin headers, tested with
cygwin 2.3, 2.5 (patch by Corinna Vinschen).
+ mention --no-collapse option in manual page description of
--tab-correct option.
+ update config.guess, config.sub
c7dd6d0193