Move REST* interfaces into pkg/api/rest

Dependency chain is now api -> api/rest -> apiserver.  Makes the
interfaces much cleaner to read, and cleans up some inconsistenties
that crept in along the way.

pkg/registry/event/rest.go

@@ -135,7 +135,7 @@ func (rs *REST) List(ctx api.Context, label labels.Selector, field fields.Select
 }
 
 // Watch returns Events events via a watch.Interface.
-// It implements apiserver.ResourceWatcher.
+// It implements rest.Watcher.
 func (rs *REST) Watch(ctx api.Context, label labels.Selector, field fields.Selector, resourceVersion string) (watch.Interface, error) {
 	return rs.registry.WatchPredicate(ctx, &generic.SelectionPredicate{label, field, rs.getAttrs}, resourceVersion)
 }