New in 5.10.1 - March 2010

* Nothing yet defined.

New in 5.10 - November 2009

* When an option is configured out (via ifdef or ifndef attributes), it is
  not normally displayed in the usage text. Sometimes, users want to know
  why the option they supplied is against the law ("illegal"). If the option
  has the omitted-usage attribute, the extended usage (via "--help") will
  now show the option name and the text:

    This option has been disabled

  Or, alternately, the text specified with the omitted-usage attribute.

  If the option is specified, the error message will be:

    PROGRAM: The MUMBLE option has been disabled

  followed by the abbreviated usage.

* Option aliasing: Several times it has been necessary to have two different
  options mean exactly the same thing. Usually, this is a consequence of
  some sort of historical use. However it came about, the need is
  there. So, AutoOpts now supports a new option attribute: aliases. This
  option will be listed in the usage text but will be handled exactly as
  if the aliased-to option were specified. You probably shouldn't use it
  unless you have to.

* AutoGen tracing output: You may now prefix a file name with shell style
  append redirection to indicate that the output appends to the file
  (i.e. >>file).

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.
