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.
If the bytes retrieved is less than the bytes we expected for the time period
we're rendering, we fill the remainder with silence. Fixes segfault trying to
copy bytes that aren't actually allocated.
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.
itsmattkc