Upload first official libgltf release: libgltf-0.0.0

News relative to previous draft version:
- Memory management improvements (fdo#81180)
- Reduced OpenGL requirements (version 3.3 -> version 3.0)
- Cleaned up API

Reviewed-on: https://gerrit.libreoffice.org/10744
Reviewed-by: Zolnai Tamás <zolnaitamas2000@gmail.com>
Tested-by: Zolnai Tamás <zolnaitamas2000@gmail.com>
(cherry picked from commit 48d1f860716720abdd7febdad4b57b9f31a6a1dc)

Conflicts:
	avmedia/source/opengl/oglplayer.cxx
	download.lst

libgltf: fix dbgutil build

(cherry picked from commit dabfe7dd025f95862e302b3c4526d382eeba19ea)

libgltf: missing <cstdio> include

(cherry picked from commit d085bba9139d882e191b46ee8056d364e7526f88)

libgltf: remove obsolete patch

(cherry picked from commit 841d50ec234e71e8e89d0e9135e2002f35fc42fa)

Change-Id: Icc5105d0668d5e4e3eb58bbaed6b2f059c30be99
Reviewed-on: https://gerrit.libreoffice.org/10747
Reviewed-by: Jan Holesovsky <kendy@collabora.com>
Tested-by: Jan Holesovsky <kendy@collabora.com>