Updates to the osg::Transform, adding preMult and postMult methods and
deprecating the old preRotate,preTranslate,preScale.
Updated the rest of the OSG so that it nolonger uses the deprecated
osg::Transform nodes.
Renamed osgUtil::SceneView::setGlobalState() to
osgUtil::SceneView::setGlobalStateSet() so that the name reflects its
functionality better. Updated osgGLUT::Viewer etc to cope with new
name change.
Also added Matrix::ensureRealized() to support the lazy initialization of Matrix, whilest keeping the implementation robust so that external calls to Matrix which get values do so on an initialized matrix.
