Service Browser takes first API key regardless of whether domain matches

The service browser will use the first entered API key regardless of whether it has the correct domain or not. You will get the "invalid API key" message even if you have a key corresponding to the correct domain available.

The attached patch makes the service browser guess the correct key based on domain. If a key corresponding to the correct domain isn't available it will warn the user that their service browser method call probably won't work and points them to the key page.