New in 5.18.6 - September 2015

* {AG,CL,GD}exe environment variables may be set to force
  bootstrapping with a particular release.
* MAN_PAGE_DATE can be used with various man page docs to
  override the current date default.
* project may now be bootstrapped and built in the source
  directory with no ill effect.
* AutoGen as a daemon will never happen.  Last vestiges gone.
* templates may now obtain the most recent source modification
  time with "(max-file-time)"

New in 5.18.5 April 2015

* Guile 1.6 is now obsolete.  1.7/8 or newer from now on.
  Fixed issues with Guile managed locale string processing.
  (It keeps getting better and better all the time and I
  must keep adjusting over and over all the time.)
* for-each handler functions may now be able to free (or not)
  the file text via the "handler-frees" attribute.

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.

New in 5.18.3 May 2014

* 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.
