Code review comment for lp:~leonardr/launchpad/publish-tokens-2

Leonard asked me to do a follow up review of http://pastebin.ubuntu.com/486435/:

The signature of check_oauth_signature() was changed and I see only one callsite changed, so if we indeed have only one callsite I think it might make sense to make the new argument (token_secret) required as it's always provided in that callsite.

Also, it'd be nice to follow the naming scheme we use for other interfaces that are divided into multiple ones based on the permissions of the attributes/methods (e.g. IFooPublic, IFooEditRestricted)?