[osg-users] Please test OpenSceneGraph master in prep for 3.5.6 dev release

[Robert Osfield]

Hi Li,

To resolve the shader selection issue I have replaced the #define/#if
usage with a new DisplaySetttings::setShaderHint() and
OSG_SHADER_HINT=GL2|GL3|GLES2|GLES3|NONE controls that enable one to
toggle the functionality at runtime.  This change is now checked into
master.  The commit was:

   https://github.com/openscenegraph/OpenSceneGraph/commit/6308b497f287a6d94fe198947168c406491ee47b