The debug message itself is rather useless, but put here in order to prevent
a compilation warning.

Mate desktop
Patch provided by Wolfgang Ulbrich <mate@raveit.de>
https://bugzilla.gnome.org/show_bug.cgi?id=778937.

This is needed to make sure that running configure from Ubuntu 12 LTS
(which happens to be the oldest targeted distribution for now) will
not have version issues with autoconf/automake/aclocal.

This is a maintainer shortcut for
--enable-deprecated
--enable-scrollkeeper
--enable-gtk-doc
--enable-gtk-doc-html
--enable-html-manuals
--enable-pdf-manuals.

- Writing target distributions in alpha order.

Which seems mandatory by Gnome rules.