Metacore plugin integration

Adds metacore plugin integration functionality
You have 11 levels of indentation. The parameters for a ajax request come a full 30 lines after a callback. There is nothing "typical" (or, for that matter, "functional"), about abusing nesting in event driven programming. If you look at other domains where events are heavily used, you will hardly see this extreme. In Android, anonymous classes used as callbacks typically just delegate to a private method, they don't have the whole implementation inline. For more analogous examples, look at any good node.js library.

To be fair, the code is not very far from the original and, with transmart having much larger problems, this is close to nitpicking. But I think you exacerbated the problem and, above all, I found your response surprising and worth addressing.

Assigning the callbacks functions to a local variable would certainly be a good development. You could also name them so they show up with nice names in the debugger. You could return from the functions early instead of having the whole function inside the body `if`. You could use jQuery exclusively instead of mixing it with Ext.js -- you wouldn't need to deserialize json by hand and you could use the deferred object methods like `then`, which really help readability. And although it would probably be overkill in this situation, the whole thing could be encapsulated in a an object.

I also  noticed now that you ignore the case when `resultJSON.success` is not truthy. I don't know if that can happen on a 200 response (would have to check the controller), but if it can't there would be no point in checking for success too.

Finally, please use spaces rather than tabs (you'll notice the previous code was using tabs).