Fixes ArcticaProject/nx-libs#303.

Attributes GH PR #307: https://github.com/ArcticaProject/nx-libs/pull/307

Attributes GH PR #304: https://github.com/ArcticaProject/nx-libs/pull/304

roll-tarballs.sh: Adapt to recent changes in nx-libs, keep legacy support for older 3.6.x and 3.5.x releases.

Attributes GH PR #299: https://github.com/ArcticaProject/nx-libs/pull/299

Attributes GH PR #300: https://github.com/ArcticaProject/nx-libs/pull/300

Attributes GH PR #298: https://github.com/ArcticaProject/nx-libs/pull/298

debian/control: B-D alternatively on libxfont1-dev or libxfont-dev. Fix FTBFS on Debian stretch which has libxfont2-dev as default now.

 Fixes ArcticaProject/nx-libs#295.

Attributes GH PR #270: https://github.com/ArcticaProject/nx-libs/pull/270

 Derived from X.org commit...

 commit 28b95fd9d1c2f078aaaac75c310a27b17c74a6fc
 Author: Kristian Høgsberg <krh@redhat.com>
 Date:   Thu Jul 6 03:25:38 2006 -0400

    Drop unused GL/include subtree.

    Woo, less Makefile's to generate.
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

 commit 2d2d38d17cc2558f8a41166a4a1578bc4c663c37
 Author: Kristian Høgsberg <krh@redhat.com>
 Date:   Fri Mar 17 01:47:25 2006 +0000

        Check for glproto when building GLX and make sure we have at least 1.4.6.
        Drop glx_ansic.h wrapper and call xalloc, xrealloc, xfree and str-funcs
            directly.

     We don't check the glproto version as we know what it is (we have our own proto file).

     Furthermore, we skip the switch from --glX<func> -> x<func> and directly switch to
     <func> (e.g. __glXMalloc() -> malloc()).
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

Attributes GH PR #251: https://github.com/ArcticaProject/nx-libs/pull/251

 From c3d14036729fd186d4ec7ca1de603e1f2d174e2f Mon Sep 17 00:00:00 2001
 From: Eric Anholt <anholt@freebsd.org>
 Date: Fri, 10 Feb 2006 22:00:30 +0000
 Subject: Remove libcwrapper usage from xorg server modules. The libcwrapper is
   only of (marginal) use in the drivers, and that usage remains.
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

 Fixes ArcticaProject/nx-libs#246 (together with merge commit
 ecd335fa).

Attributes GH PR #294: https://github.com/ArcticaProject/nx-libs/pull/294

 Fixes ArcticaProject/nx-libs#188.

Attributes GH PR #280: https://github.com/ArcticaProject/nx-libs/pull/280

Attributes GH PR #279: https://github.com/ArcticaProject/nx-libs/pull/279
Fixes ArcticaProject/nx-libs#264.