Copyright for glibc-doc-reference source package in Bionic

This is the Debian prepackaged version of the GNU C Library Reference Manual version 2.9

For licensing reasons, the GNU C Library Reference Manual cannot be distributed
in Debian and has to be shipped in the non-free section.  It has been
repackaged by the GNU Libc Maintainers  from the
following source:

   https://sourceware.org/git/glibc.git


The following applies to the GNU C Library Reference Manual (libc.info):

   Copyright (C) 1993-2017 Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
   under the terms of the GNU Free Documentation License, Version 1.3 or
   any later version published by the Free Software Foundation; with the
   Invariant Sections being "Free Software Needs Free Documentation" and
   "GNU Lesser General Public License", the Front-Cover texts being "A
   GNU Manual", and with the Back-Cover Texts as in (a) below. A copy of
   the license is included in the section entitled "GNU Free
   Documentation License".

   (a) The FSF’s Back-Cover Text is: "You have the freedom to copy and
   modify this GNU manual. Buying copies from the FSF supports it in
   developing GNU and promoting software freedom."

On Debian systems, the complete text of the GNU Free Documentation
License Version 1.3 can be found in `/usr/share/common-licenses/GFDL-1.3'.