tizen: kdbus: Add kdbus

tizen: kdbus: Add kdbus

This commit provides kdbus originally from upstream but later long
maintained and significantly improved for Tizen project by Lukasz Skalski,
Adrian Szyndela, Hyotaek Shim, Insun Pyo and Michal Eljasiewicz.

See tizen_8.0 and older branches for complete history. The commits below
list only the start of kdbus history (for identifiaction purposes).

.

commit f8c5231931f3a0d7b0508598e3f51e5cef13017f
Author: Lukasz Skalski <l.skalski@samsung.com>
Date:   Fri Aug 21 17:42:53 2015 +0200

    gdbus: integrate kdbus into GDBus core

    Patch includes also changes made by Ryan Lortie <desrt@desrt.ca>

    https://bugzilla.gnome.org/show_bug.cgi?id=721861

    Change-Id: I6bab6fee34787816efeb42d8e3e60c4c551a8a2b

commit d2e6e8fd848d104a4ae83af5eced5cf009b5f29c
Author: Lukasz Skalski <l.skalski@samsung.com>
Date:   Fri Aug 21 17:41:27 2015 +0200

    gdbus: add kdbus core files

    Patch includes also changes made by Ryan Lortie <desrt@desrt.ca>
    and Adrian Szyndela <a.szyndela@samsung.com>

    https://bugzilla.gnome.org/show_bug.cgi?id=721861

    Change-Id: Ie90076a28c611320cd9b5ed6f2123d0ef85c6326

commit 2eae20f44d0300b3d151ae8a1f260bf122da702a
Author: Lukasz Skalski <l.skalski@samsung.com>
Date:   Fri Aug 21 16:47:05 2015 +0200

    gdbus: import kdbus interface header

    kdbus.h taken from https://github.com/systemd/kdbus, commit 9c04b6b989c9.

    Hosting of our own copy of the kdbus header is temporary solution.
    In the future, we should include it from the system kernel headers.

    https://bugzilla.gnome.org/show_bug.cgi?id=721861

    Change-Id: I2a42c91648b10c7c14f4df9ce2755f7c60524903