Gengetopt 2.20

I released version 2.20 of GNU Gengetopt.

As usual, this new release fixes some bugs:

If --include-getopt is specified then the generated parser is actually independent of getopt.h; this way, the included getopt functions code, which will actually be used, will not conflict with possible signatures found in getopt.h; moreover, if getopt.h is not present in the system at all, you won't get an error (bug fixed thanks to Tiago Menezes).

In the --help output a section name and description will not be generated if all its options are hidden (thanks to Edsko de Vries).

I've added the command line option --default-optional that permits specifying that all options are by default optional (unless explicitely specified). In fact, up to now, all options were considered mandatory if not specified otherwise; this might not be a comfortable behavior, but I couldn't change it without breaking existing code... but if you use this command line option for gengetopt, you'll avoid this possible unwanted behavior.

A bug was fixed in the included getopt functions code when --include-getopt is specified.

Finally, I fixed a bug when using args entry in the .ggo file (thanks to Christian Gagneraud). In fact, if in the args entry you specify options such as --file-name the memory was corrupted with possible unexpected behavior. Moreover, now all the options specified in the args entry are taken into consideration.