set the uri id in the request data

Otherwise, if the id is not in the request data - an insert is
performed, not an update.

Requires test changes as thoe model alias is not set for mocked Model
class instances
verify that it works with both expected data formats
Validate the model id if it's in the data

it should match the id in the url or something's not right and probably
it's a malicious request
verify that the user isn't trying to edit somethign else

And if they are - throw an exception
add missing doc block
simpler logic for getting the data-id
remove unused variable
Merge pull request #75 from jippi/feature/edit-id

set the uri id in the request data