PositionAttitudeTransform, removed the equivialnt callbacks once found in these
transform classes.
Changed the NodeCallback class so its derived from osg::Object instead of
osg::Referenced to allow it to be saved out in the .osg format.
Added support for Update and Cull callbacks into the .osg file format.
Added support for AnimationPathCallback into the .osg file format.
the osgGA::AnimationPathManipulator to handle it.
Added a new Drawable::ConstAttributeFunctor and make the accept(PrimitiveFunctor)
be a const method so can disallows modification. Added Drawable::supports(...) methods
for each of the AttributeFunctor, ConstAttributeFunctor and PrimitiveFunctor so
that programs can querry whether it is possible to use functors with that object type.
the clash with the parameter type itself.
Addd a PER_PRIMTIIVE_SET handling to the existing PER_PRIMTIIVE code, this code
is still flacky though and needs a rewrite as it doens't handle all attributes or
the full consequences of per primitive and per primitive set bindings.
osg::PositionAttitudeTransform::AnimationPathCallback which us an app callback
which uses an AnimationPath to specify the new positions of the transform.
Added AnimationPath code to osglight to animate the positional light.
Added CullVisitor::setCullingMode() code into SceneView so that SceneView's
CullingMode is now properly passed onto CullVisitor. Note, this work
had been done before, but must has been lost in a merge. Umm...
Converted AnimationPath so it is now subclassed from osg::Transform::ComputeTransfromCallback()
so that it can be directly attached to the scene to move objects about.
Changed the osg::SateSet::setGlobalDefaults() so that is sets GL_DEPTH_TEST
to ON.
Added guards and creation of default helper classes in osgGLUT::Viewer and
osgUtil::SceneView so that sensible defaults are used when no settings
are used of osg::State/StateSet,osgUtil::RenderStage/RenderGraph/CullVisitor.
