Largely conforming renderers to new NodeValue system. Code seems a lot cleaner
this way which is a nice advantage. Likely non-functional as this won't
compile just yet and still needs probably another day or two of testing to get
it back to where it was before.
Old code assumes that a NodeParam's parent will always be a Node. The function
has been separated off and tweaked in the event that this is not the case.
Updating values rapidly would cause strange jitters as a
byproduct of the viewer trying to update from the renderer while
it was still working. Rather than the viewer trying to access the
the renderer, we now send textures in the initial update signal
to keep everything synchronized.
Major refactoring work to try sharing as much code as possible between the
video renderers and audio renderers, as well as make them as
platform-independent as possible.