Allow multiple Redirect URIs for a client

On the client registration form, only one Redirect URI is allowed per client. In some cases it is useful to have more than one redirect_uri per client. For example you may have more than one domain for the same application. Or you may have a test and dev site besides the live one. Or you may have an application that has more than one oauth2 client (each one of them needs its own Redirect URI). In all these cases it is more suitable and reasonable to register more than one Redirect URI per client, than to register multiple clients.