Very rough implementation of passing shape data from Graphics objects to the rendering backend

@yurydelendik, this should at least give you something to work with as far as the shape data is concerned. It doesn't yet do anything with the passed data - I'll flesh that out next.

One thing I realized is that it's hard to impossible to implement an efficient implementation of a shape renderer without having `IDataOutput` available in GFX code. For now, I just added a reference to `bytearray.ts`, but since we don't want GFX to depend on AVM2, we'll have to figure out something else. Perhaps just duplicating the interface is ok.