Custom attribute in modals

@reciprocitylaran This adds custom attributes to the modals, but custom attribute values are not loaded yet (I'll start working on this next).

I am however sending the custom attribute values back to the server, so that you can see if you can make saving work on the backend. This is how the POST/PUT Request looks like:

![screen shot 2014-11-26 at 16 14 17](https://cloud.githubusercontent.com/assets/513444/5210822/9c195f34-7588-11e4-8184-bfb528b61cc6.png)

I'll also check if there is a cleaner way of sending custom attribute values to the server (maybe the same way as brad implemented objects in audit modal), but I'm not sure if that is going to work.

Let me know if you get stuck trying to save custom attributes from the POST/PUT requests.