apply method. This order is intended to help support of vertex programming, but
unfortunately breaks the osgreflect demo so the original ordering is kept by default.
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.
it now maintains references to the last applied matrices, automatically doing
lazy state updating. This simplifies the various places in the OSG which
were previously doing the applying, add paves the way for managing the
projection matrix within the scene graph.
Remove MemoryAdapter and mem_ptr as they arn't being used, and can potentially
confuse users by their existance.
Moved CullVisitor/RenderStage/RenderStageLighting across to managing lights
entirely within RenderStageLighting, and changed the management of modelview
matrices so that RenderLeaf now stores the absolute modelview matrix, rather
than a model matrix as done previously. The later allows RenderLeaf's to do
a glLoadMatrix rather than a glPushMatrix/glMultMatrix/glPopMatrix.
