Complete Physics2D, add handling of full API with thisObject parameter
shit, wrapping meethods on Haxe side via TZJS.wrap#. Unfortunately,
whilst the Broadphase type is very nicely represented in Haxe, due to
the wrapping requirements for thisObject crap it can't be an interface
and it would not be possible to create new broadphases from Haxe side
I do not think.