Remove inheritance logic for relationships and actions

In _services_process_resource() at line 161 of services.resource_build.inc, there is code which makes relationships, actions, and targeted actions inherit properties from previously defined resources if they are not present. Relationships inherit from 'retrieve', while actions and targeted actions inherit from 'update'. I find this really confusing. I'd rather have all the properties be explicitly stated in the resource definition, which is clearer and open to less confusion. I just lost a hour or so chasing down a problem where I had set a relationship's access callback to be nothing (implying it should use user_access()) but instead it kept getting replaced with the retrieve resource's access function. Even if the inheritance thing doesn't get pulled out, that is actively a bug.

Comments?