Makefile: Adapt install target to the new situation where we fake X11 headers in .build-export. This fixes FTBFS during file installation into .deb and .rpm packages.

  - Update XErrorDB to latest X.org version.
  - Install XErrorDB, XKeysymDB and Xcms.txt to /usr/{local/}share/nx/.
  - Assure that libNX_X11 finds those files at the
    named location.
  - Update debian/ packaging files.
  - Update nx-libs.spec packaging file.

Fixes ArcticaProject/nx-libs#153

  o Install nxagent/nxproxy executables into multi-arch path.
  o Fake libNX_X11.so* as $LIBDIR/nx-X11/libX11.so*.
  o Allow injecting different $NXAPP containing the executable name.

  o For e.g. x2goagent this requires the following changes:

    - Move x2goagent symlink from /usr/lib/x2go/bin/x2goagent to
      $LIBDIR/nx/bin/x2goagent
    - Replace /usr/bin/x2goagent by a two-liner...

    ```
    #!/bin/sh

    export NXAPP=x2goagent
    nxagent
    ```

 Note:

  - The "normal" way to inject CFLAGS (and CPPFLAGS) into nx-X11 builds is copying those
    options over into the variable CDEBUGFLAGS.
  - LDFLAGS have to be handed to nx-X11 via LOCAL_LDFLAGS.

 This change also includes a slight change in the nx-X11 build order.

 Old build order:

  Main Makefile:

      - [...]
      - libNX_X11
        + implicitly building nxcomp
        + implicitly building nxcompext
      - [...]
      - nxagent
        + implicitly building nxcompshad
      - [...]

 New build ordner:

  Main Makefile:

      - [...]
      - nxcomp
      - setup nx-X11 build env
        + cd nx-X11 && make BuildEnv
      - nx-X11/lib/*
      - nxcompext
      - nxcompshad
      - [...]
      - nxagent
      - [...]

 Fixes ArcticaProject/nx-libs#141
 Fixes X2GoBTS#84

 Note:

  - The "normal" way to inject CFLAGS (and CPPFLAGS) into nx-X11 builds is copying those
    options over into the variable CDEBUGFLAGS.
  - LDFLAGS have to be handed to nx-X11 via LOCAL_LDFLAGS.

 This change also includes a slight change in the nx-X11 build order.

 Old build order:

  Main Makefile:

      - [...]
      - libNX_X11
        + implicitly building nxcomp
        + implicitly building nxcompext
      - [...]
      - nxagent
        + implicitly building nxcompshad
      - [...]

 New build ordner:

  Main Makefile:

      - [...]
      - nxcomp
      - setup nx-X11 build env
        + cd nx-X11 && make BuildEnv
      - nxcompext
      - nxcompshad
      - nx-X11/lib/*
      - [...]
      - nxagent
      - [...]

 Fixes ArcticaProject/nx-libs#141
 Fixes X2GoBTS#84

 The x2goagent package is being replaced by an x2goserver bin:package
 named x2goserver-x2goagent.

 This x2goserver-x2goagent bin:package will be maintained in the X2Go
 Project's namespace and basically wraps around nxagent.

 Furthermore, declare Arctica Project as upstream source for nx-libs.

X2Go Agent: Add x2goagent.features file that informs X2Go clients about the new RandR based Xinerama feature.

library clean-up: Don't build libNX_Xinerama anymore. Use system's libXinerama shared library. (Fixes ArcticaProject/nx-libs#49).

 This commit goes along with a patch from Ulrich Sibiller who managed to
 move the Xinerama awareness for NX sessions into the Xserver code. This
 makes Xinerama support for NX in libNX_Xinerama.so obsolete.

 Fixes ArcticaProject/nx-libs#49

 In the process of building nxagent against more and more system-wide installed
 X.org libraries, we come to the limit of including structs from this (bundled
 nx-X11) and that (system-wide X.Org) library.

 This commit introduces a clear namespace separation of headers provided by
 nx-X11 and headers provided by X.Org. This approach is only temporary as we
 want to drop all nx-X11 bundled libraries from nx-libs.

 However, for a while we need to make this separation clear and also ship
 some reduced fake X.Org headers that avoid pulling in libX* and libNX_X*
 symbols at the same time.

 This patch has been tested on Debian jessie and unstable and requires no
 overall testing on various distros and distro versions, as we finally will
 drop all libNX_X* libraries and build against X.org's client libs.

 For now, this hack eases our development / cleanup process.

debian/libnx-xinerama1.*: move Xinerama dir back to nx-x11-common. Only delete known files. Fixes RPM build failures.

Due to the nx-x11-common package being a noarch/allarch package,
creating the symlink in nx-libs' Makefile will lead to the symlink
referencing the "default" architecture dpkg uses for building
noarch/allarch packages.

Incidentally, this worked fine for Debian, as amd64 seems to be the
default architecture. On Ubuntu, however, the default architecture up to
Vivid (15.04) was i386. For those builds, the symlink pointed to the 32
bit library of libNX_Xinerama.so.1 -- essentially breaking this feature.

Move the symlink creation to the arch-sensitive libnx-xinerama1 package.
The postinst and prerm scriptlets will work fine, unless someone
installs the i386 package version *after* the amd64 version. Given that
we already create symlinks to libNX_X11 and friends using that method,
no new regression is introduced. Strictly speaking that's a bug, but
we'll hopefully clean that up later...

  This feature copies the way how X.Org version string and number
  are propagated at build time.

  First use case: if people start nxagent, it reports its version number
  on stderr. This is about being human-friendly.

  Second use case: None, so far. But it will now be easy to use
  the NXAGENT_VERSION_STRING in later feature add-ons.

Makefile.nx-libs: Fix uninstall-lite rule. The nxproxy and nxcomp uninstallation has to be in uninstall-lite, not in uninstall-full.

Conflicts (resolved by Mike Gabriel):
	debian/changelog

    debian/roll-tarballs.sh
    debian/rules
    nx-libs.spec

  * Debian/Ubuntu packaging:
    + Fully rework the way nx-libs gets packaged for Debian/Ubuntu.
    + Split up libnx-x11 into individual packages.
    + Provide dbg:packages for each bin:package containing binaries.
    + Use Makefile logic to install files into DESTDIR.
    + Provide dev:packages for each lib:package individually.
    + Provide nx-x11proto-*-dev packages for all libnx-* libraries.
    + Install _all_ library files (*.so*) to /usr/lib/<triplet>/, so
      no extra settings of LD_LIBRARY_PATH is necessary.

Provide a default keystrokes.cfg in /etc/nx (for nxagent) and /etc/x2go (for x2goagent). (Fixes: #199).

Fix faulty symlink path. Make sure that x2goagent symlink does not point to absolute path somewhere within the build environment.

Main Makefile: Use absolute symlink when linking from $(X2GOLIBDIR) into $(NXLIBDIR) (i.e. linking x2goagent -> nxagent). (Fixes: #143).

Work-in patch from Jan Engehardt for working around different improper bash implementations of string-in-string replacing. (Fixes: #145).

Continue Reinhard's work on top-level install/uninstall. Esp. integrate debian/post-nx-build.sh into main Makefile. Make value of CONFIGURE variable traversable through the Makefile tree.

Instead, place the makefile into debian/Makefile.nx-libs. This makes the
makefile easier to edit.