extends in webinterop

[Sharktheone]

We need some system, so we can use some kind of extends in the scripting part.

Internally, this will just be a field that holds the struct we want to extend from. For example, if we have a UIEvent struct that we pass to js/Lua we will have a field event or parent with a Event. When creating the bindings, the Event's implement function will be executed before the UIEvents, which leads to the fields on the Object being correctly instantiated for all struct/classes we that we inherit from.

However, there needs to be a slightly different function, so we can also modify the Object's prototype accordingly.