Doc: Include full LinuxDocTools code

BIRD uses hacked LinuxDocTools for building documentation, keeping some
parts locally and using remaining parts from system-installed one. This
setup breaks when LinuxDocTools makes some internal changes and is hard
to keep consistent.

Just include full LinuxDocTools code (both hacked and unmodified parts)
to avoid consistency issues. Note that we still need some binaries from
LinuxDocTools, so it still needs to be installed to build documentation.

1 files changed, 85 insertions, 0 deletions

diff --git a/tools/linuxdoc-tools/copyright b/tools/linuxdoc-tools/copyright
new file mode 100644
index 00000000..a89b6ada
--- /dev/null
+++ b/tools/linuxdoc-tools/copyright
@@ -0,0 +1,85 @@
+
+This is `linuxdoc-tools', a series of tools to implement the Linux
+Documentation Project HOWTO and book styles in SGML.
+
+This copy was modified in order to work with birddoc DTD. It is
+based on version 0.9.73-2 from Debian 10.
+
+
+----------------------------------
+    The linuxdoc-tools license
+----------------------------------
+
+linuxdoc-tools is derived from linuxdoc-SGML, originally written by
+Matt Welsh and later maintained by Cees de Groot. Linuxdoc-SGML is
+based on James Clark's sgmls parser, and the QWERTZ DTD by Tom
+Gordon. Magnus Alvestad provided the current HTML support. For
+the rest of linuxdoc-SGML,
+
+  Copyright (C) 1994-1996 Matt Welsh <mdw@cs.cornell.edu>
+  Copyright (C) 1996-1998 Cees de Groot <cg@pobox.com>
+
+Original Linuxdoc-SGML itself does not have any limitations.
+Everything not having explicit additional conditions can be freely
+used, modified, and redistributed, under the usual fair use clauses:
+
+ * No warranty. Use at your own risk.
+ * Do not pretend to have written what you did not (Preserve credits
+   and Copyright notices of the different elements if present).
+
+Since then, lots of smaller and bigger changes resulted in a rename
+to SGML-Tools (and then to SGMLtools, the hyphen caused confusion)
+to indicate that it wasn't just for Linux anymore. See files
+CHANGES.old-v1 and CONTRIBUTORS.old-v1 for changelog and list of
+contributors to old linuxdoc-sgml and sgmltools-v1.
+
+When sgml-tools dropped support for the linuxdoc DTD, Taketoshi Sano
+<sano@debian.org> forked the code to linuxdoc-tools. See README file.
+
+Changes after the fork
+
+  Copyright (C) 1999-2002 Taketoshi Sano <sano@debian.org>
+  Copyright (C) 2000      Juan Jose Amor
+  Copyright (C) 2007-2018 Agustin Martin Domingo <agmartin@debian.org>
+
+Unless conflicting with other licenses, changes by Agustin Martin
+Domingo are free software: you can redistribute and/or modify them
+under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version. Otherwise they honour previous
+license.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+In Debian systems you can find a copy under /usr/share/common-licenses.
+
+
+----------------------------------
+    The entity-map license
+----------------------------------
+
+Copyright (C) 1997 Ken MacLeod
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL KEN MACLEOD BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
+OR OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of Ken MacLeod shall not
+be used in advertising or otherwise to promote the sale, use or other
+dealings in this Software without prior written authorization from
+Ken MacLeod.