preparing for a new gtk-doc release

[Stefan Sauer <ensonic hora-obscura de>]

hi,

did anyone try the new toolchain yet? In configure.ac all you need to do is:

-GTK_DOC_CHECK([1.14])
+GTK_DOC_CHECK([1.29],[--flavour no-xslt])

for meson/cmake I have no idea and would glady take patches. The
advantage of the new toolchain is that you won't need xsltproc +
docbook-stylesheets and that it is much faster, but instead a few more
python modules - see README:

https://gitlab.gnome.org/GNOME/gtk-doc/blob/master/README

If you try it out, you might see some warnings of not yet supported
docbook tags. If you encounter stuff that is not easy to get rid of,
please let me know (eg file a bug report).

I also look forward to get before after numbers.

If I don't get any bug reports in the comming week, I'll cut a 1.30 release.

Stefan