fix error with extendable 'methods' not being added to instance

The diff should be self-explanatory. I think this was just a typo.

I'm not able to use the statics option in any useful way, as all I have access to inside a 'static' function is the constructor Function itself, is there some way I can use static to access things like this.properties? (From my model, but before I've instantiated a new instance of the model)