Automatic merge from submit-queue
Adding events to federation control plane
Adding events to federation control plane.
Apart from the standard changes to add a resource to `federation/apis/core/v1`, other changes are:
* Adding a new `federationoptions.ServerRunOptions` which includes `genericoptions.ServerRunOptions` and EventsTTL.
* Added a new method in `pkg/api/mapper` to build a RestMapper based on the passed Scheme rather than using `api.Scheme`. Updated `federation/apis/core/install` to use this new method. Without this change, if `federation/apis/core/install.init()` is called before `pkg/api/install.init()` then the registered RESTMapper in `pkg/apimachinery/registered` will have no resources. This second problem will be fixed once we have instances of `pkg/apimachinery/registered` instead of a single global singleton (generated clientset which imports `pkg/api/install` will have a different instance of registered, than federation-apiserver which imports `federation/apis/core/install`).
cc @kubernetes/sig-cluster-federation @lavalamp