[swfmill] Flash9 support

[Ralf Fuest]

Hello Mark,
you are right. You just use "class Foo extends BytaArray {}". At least
it works in haXe this way, I don't know about AS3.

Ralf

> Yeah, swfmill doesn't even use a hack. My approach was to abuse
> DefineBitsLossless2 and to turn it into a ByteArray on the client. I
> had no idea there was something like DefineBinaryData.
> Writing that tag seems straight forward, but what will it be on the
> client? How do I use it? MyBinaray extends ByteArray?