osg::Camrea::getModelViewMatrix() and osg::Camera::getProjectionMatrix() are
calculated on the fly. Removed various redudent methods, including the
project and unproject methods which are better supported within osgUtil::SceneView.
Added a computeWindowMatrix() method to Viewport, to make it easier to construct
a MV*P*W matrix for converting local coords into screen coords and visa versa.
Converted SceneView and CullVisitor to use this new method.
support out of Camera and into SceneView. Also enabled the option to set the
projection and modelview matrices directly on SceneView thereby removing the
dependance on osg::Camrea to control the view of the scene.
in progress for the new support for controlling the projection matrix from
within the scene graph.
Also Added osg::State::getClippingVolume(), getProjectionMatrix() and
getModelViewMatrix() with allows drawables to access the current projection,
and model view matrices and the view frustum in local coords to the drawable.
Renamed the osg::VisualsSettings to osg::DisplaySettings, and
osgUtil::VisualsRequirementsVisitor to osgUtil::DisplayRequirementsVisitor.
Added support for OSG_SCREEN_HEIGHT into osg::DisplaySettings, and added
a DisplaySettings* to the constructors of osg::SceneView and osg::Camera.
