* Noteworthy changes in Version 1.4.10b (2008-02-25) [beta]
  Released by Eric Blake, based on git version 1.4.10a

** Security fixes for the -F option, for bugs present since -F was
   introduced in 1.3: Avoid core dump with 'm4 -F file -t undefined', and
   avoid arbitrary code execution with certain file names.

** Fix regression introduced in 1.4.9b in the `divert' builtin when more
   than 512 kibibytes are saved in diversions on platforms like NetBSD
   where fopen(name,"a+") seeks to the end of the file.

** The output of the `maketemp' and `mkstemp' builtins is now quoted if a
   file was created.  This is a minor security fix, because it was possible
   (although rather unlikely) that an unquoted string could match an
   existing macro name, such that use of the `mkstemp' output would trigger
   inadvertent macro expansion and operate on the wrong file name.

** Enhance the `defn' builtin to support concatenation of multiple text
   arguments, as required by POSIX.  However, at this time, it is not
   possible to concatenate a builtin macro with anything else; a warning is
   now issued if this is attempted, although a future version of M4 may
   lift this restriction to match other implementations.

** Enhance the `index' builtin to guarantee linear behavior and often
   acheive sublinear results, in spite of the surprisingly large number of
   systems with a brain-dead quadratic strstr(3).

** Enhance the `regexp' and `patsubst' builtins to cache frequently used
   regular expressions, which speeds up typical Autoconf usage.

** Enhance the `format' builtin to warn for more suspicious usages, such as
   missing arguments or problems parsing according to the format string.

** Enhance the `ifelse' and `shift' builtins so that tail-recursive
   algorithms based on `$@' operate in linear, rather than quadratic, time
   and memory.

** A number of portability improvements inherited from gnulib.