New in 5.9.9 - August 2009

* options may now be "deprecated".  They get processed, but do not show
  in the usage output.

* options may be marked "no-command", meaning they are not to appear on
  the command line.  Thus, they are recognized in config files only.

* "disable-save" and "disable-load" may be used to prevent the command
  line options from loading or saving options from/to a file.

New in 5.9.7 December 2008

* several cleanups.
* "more-help" is only supported with libopts is in use at run time.
  Allow for it to be expunged from the documentation.
* Add a #define for the configured shell to config.h
* add --used-defines to autogen.  You can now find out all the names
  that autogen looked up during processing.  That will include computed
  names and values passed to macros by name and it won't include names
  only referenced in sections of a template that were not processed.
  But it helps in documenting a template anyway.

New in 5.9.6 November 2008

* Hierarchically valued options can now be stored with ``--save-opt'' option

* option state may now be "reset".  This is indistinguishable from the
  compiled state.  If option state is "saved" later, such an option will
  not appear in the save file.

* there is a new option argument type:  time.  Its argument string
  represents years (?!), months, weeks, days, hours, minutes and seconds.
  The value seen by the program is an integer number of seconds.
  (This is not a date/time.)  The duration of a year is always 365 days
  and the duration of a month is always 30 days.
