Ensure API calls are held to same restrictions in real API

[idjaw]

Currently, the Fake-UB API is very lenient and the data that is returned is very minimal. Furthermore, it will return any extra parameters we send as data, which works contrary to how Ubersmith works.

While Ubersmith will accept any extra parameters sent to it when retrieving this data, only the data supported by the API will be returned.

Example problem:

Calling a client.add with unsupported arguments like: x='foo', y='bar' will result in those parameters being returned in a subsequent client.get.

This should not happen. We should be lenient in accepting, but only show the supported parameters.

This should be done for all implemented calls.