In general glTF shader files does not contain version
directives and in some case it make shader compiler
using GLSL 1.1 which leads to that the shader compiler
fails.
So we need to append the choosen version number which is
GLSL 1.3 in case of libgltf, but this also means that
from that point OpenGL 3.0 is the new reuirements since
GLSL 1.3 is available only from that version.

Change-Id: Ic4382266432ea474aeb3e603b32a998b9aeed280