handle scenes with multiple views with elements that need coordinating on a per view basis.
Added beginings of new osgText::FadeText class (not functionality yet).
"I've made some changes to osg which I think make it easier to control
the render order of CameraNode's. Instead of using the built-in orders
(PRE_RENDER, POST_RENDER, NESTED_RENDER), you can specify an integer
order. Values less than zero are pre rendered in order. Values greater
than zero are post rendered in order. And a value of 0 is equivalent
to NESTED_RENDER.
The changes should be fully backward compatible. Also, I changed the
RenderStageList type from a vector to a list because I needed to be
able to insert values anywhere in the list.
The reason I made these changes was because I wanted to be able to set
the render order of a CameraNode at runtime without having to reorder
it in the scenegraph."
and later in the final submission message (relating to what has been finally been merged) :
"I've rethought my implementation and came up with something a little
better. The setRenderOrder will continue to take an enum, but will
have an optional orderNum parameter which can be both positive and
negative. I think this method is more intuitive and flexible."
