New in 5.18.4 - August 2014

* Do Not Edit (dne) warning:  the default of printing a date in the
  warning has now changed to not doing so.  The "-d" option to
  suppress the date is now deprecated (ignored).  A new option, "-D"
  will cause the date to be included.  The environment variable,
  "AUTOGEN_DNE_DATE" overrides everything.
* The RETURN function was not completely implemented and only
  partially worked.  It is working now.
* optionPrintVersionAndReturn() is a new function for applications
  that wish to extend the behavior of the "--version" option.
* mdoc and man pages have been greatly improved.
* libopts tear-off library used stdnoreturn.h and now includes
  infrastructure for systems deficient in that area
* new function: insert-file  It will simply insert the contents of
  a file (or list of files) into the output stream.

New in 5.18.3 May 2014

* ATTRIBUTE_FORMAT_ARG is a configured attribute that wraps
  __attribute__((__format_arg__(n))) procedure declaration attributes.
  To configure it, the ag_macros.m4 has a new macroo,
  AG_COMPILE_FORMAT_ARG (which is a compile only test probe).

* Auto-edit Guile headers that depend upon configure values
  most especially:  noreturn
  but check for "ptrdiff_t" in our configure too, so that Guile does
  not create its own duplicate definition.

* Abort from the failing function so that stack traces are useful
* The libopts m4 configure code must configure the libopts/Makefile
* Happy 2014 New Year
* make sure library option handling code does nothing when the
  library is just trying to get information about an option.
* Only apply texi2mdoc when it is needed.
* The aoGetsText() emitted i18n helper function needs its argument
  to have the "format_arg" attribute.

New in 5.18.2 October 2013

* documentation clarifications
* properly create generated main procedures from user supplied code.
* ChangeLog files have been removed from GIT sources
  (though still obtainable with tagged checkouts).
* LIBGUILE_PATH is not needed and its derivation is wrong on
  where binaries and libraries have different prefixes.
