Move initialization of Array.prototype to TS

Thus making Array completely native.
Fix warnings about two out of three missing natives for XMLList

No idea yet what's up with XMLList#descendants.
Make DebugBounds compatible with Bounds again

But don't activate it: we have lots of asserts because of bugs in setting Bounds values.
Stub out XMLList#descendants
Remove AS3 declaration of unused native function Proxy::flash_proxy::isAttribute