libasprintf: Use a version of texi2html which is under a good license.
Reported by <ineiev@gnu.org> in <https://savannah.gnu.org/bugs/?54809>.
* gettext-runtime/libasprintf/texi2html: Copied from texi2html-1.78, with
changes made in libunistring/build-aux/texi2html and then in
libtextstyle/build-aux/texi2html.
* gettext-runtime/libasprintf/fdl.texi: New file, copied from
gettext-tools/doc/fdl.texi.
* gettext-runtime/libasprintf/gpl.texi: New file, copied from
gnulib/doc/gpl-2.0.texi.
* gettext-runtime/libasprintf/lgpl.texi: New file, copied from
gnulib/doc/lgpl-2.1.texi.
* gettext-runtime/libasprintf/autosprintf.texi: Invoke @contents. Enable the
Top node during texi2html processing.
(Licenses): New appendix.
* gettext-runtime/libasprintf/Makefile.am (TEXINCLUDES): New variable.
(MAKEINFOFLAGS): Use it.
(autosprintf_TEXINFOS): New variable.
(autosprintf_all.html): Depend on it. Use texi2html options -no-sec-nav -no-menu
-toc-links.
