just as Xorg upstream did

Makefile: Make sure libNX_X11.so.6.2 does not get installed as symlink but as actual file. (Follow-up for 5a90a638).

Attributes GH PR #267: https://github.com/ArcticaProject/nx-libs/pull/267

although upstream still includes it.

might be reintroduced later when upgrading the server

was unused

never used

We do not build loadable modules, so we do not need them anywhere.

Also remove the extra files requires for module builds.

This backports (in their essence) these X.org Xserver commits:

 commit a7a2f9f66ddc27df96557093f3dd266e24eb653b
 Author: Daniel Stone <daniel@fooishbar.org>
 Date:   Tue Jul 10 02:03:13 2012 +0100

    Remove the last remnants of extmod

    extmod was originally a big pointless module.  Now it's an empty,
    pointless module.  This commit makes it unexist.
Signed-off-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

 commit 7a11b817e770cd2196814f1ac6264c6d87b76c6a
 Author: Tomas Carnecky <tom@dbservice.com>
 Date:   Tue Jul 10 02:03:06 2012 +0100

    Move Xv and XvMC from extmod to built-in

    Always build these extensions into the core server, rather than letting
    them languish in extmod.
Signed-off-by: Tomas Carnecky <tom@dbservice.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

 commit 7d859bd87834dd79c7fa3792075496ece698c082
 Author: Tomas Carnecky <tom@dbservice.com>
 Date:   Tue Jul 10 02:03:05 2012 +0100

    Move XRes from extmod to built-in

    Always build XRes support into the core server, rather than letting it
    languish in extmod.
Signed-off-by: Tomas Carnecky <tom@dbservice.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

 commit ba21fc29587e4f11320b88a70433beb1fe22cdf3
 Author: Tomas Carnecky <tom@dbservice.com>
 Date:   Tue Jul 10 02:03:04 2012 +0100

    Move DPMS from extmod to built-in

    Always build DPMS support into the core server, rather than letting it
    languish in extmod.
Signed-off-by: Tomas Carnecky <tom@dbservice.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Keith Packard <keithp@keithp.com>

 commit 3ed2c6e11298c4299042cfe4578f6cc02e441d58
 Author: Tomas Carnecky <tom@dbservice.com>
 Date:   Tue Jul 10 02:03:03 2012 +0100

    Move MIT-SCREEN-SAVER from extmod to built-in

    If we've built MIT-SCREEN-SAVER support, then just build it into the
    main binary, rather than leaving it in extmod.
Signed-off-by: Tomas Carnecky <tom@dbservice.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

Conflicts:
	nx-X11/programs/Xserver/Xext/extmod/Imakefile

Attributes GH PR #248: https://github.com/ArcticaProject/nx-libs/pull/248

Create libX11* link in exports/lib. This simplifies running nxagent
from the build directory.

This also adds a clean rule to remove the libX11 links as well as the
libNX_X11 links which was not done before.

Fixes ArcticaProject/nx-libs#234

Attributes GH PR #254: https://github.com/ArcticaProject/nx-libs/pull/254

 Fixes ArcticaProject/nx-libs#250.

Attributes GH PR #266: https://github.com/ArcticaProject/nx-libs/pull/266

 commit f31bd087e8a7f65cd588bd1d022bb18e72b2a60c
 Author: Adam Jackson <ajax@redhat.com>
 Date:   Fri Jun 13 10:35:07 2008 -0400

    Death to mfb.

    Anyone still interested in 1 or 4 bpp framebuffers, talk to fb.
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

 commit 748cfbc820f8cdeb544c54a6db495fecf2e2457b
 Author: Adam Jackson <ajax@aspartame.nwnk.net>
 Date:   Sat Nov 17 21:23:05 2007 -0500

    Disinfect mi/ of mfb.
Backport-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

Attributes GH PR #258: https://github.com/ArcticaProject/nx-libs/pull/258

 Fixes ArcticaProject/nx-libs#255.

Attributes GH PR #260: https://github.com/ArcticaProject/nx-libs/pull/260

Attributes GH PR #247: https://github.com/ArcticaProject/nx-libs/pull/247
Reviewed by: Ulrich Sibiller <uli42@gmx.de>  -- Fri, 28 Oct 2016 15:29:43 -0700

Imake.rules: Make BuildIncludes{,Top}() more robust in case people attempt providing path names instead of file names via srclist.

Fixes ArcticaProject/nx-libs#223.
Fixes ArcticaProject/nx-libs#244.

Attirbutes GH PR #249: https://github.com/ArcticaProject/nx-libs/pull/249

This is part one of ArcticaProject/nx-libs#246

version.def and date.def also will be no longer created