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.
encapsulates.
Added new osg::IndexGeometry implemention, *not* complete yet.
Changed the rest of the OSG to handle the renaming og Primitive to PrimitiveSet.
