Make runtime less global for Codec

* Make Codec separate from Scheme
* Move EncodeOrDie off Scheme to take a Codec
* Make Copy work without a Codec
* Create a "latest" package that imports all versions and
  sets global defaults for "most recent encoding"
  * v1beta1 is the current "latest", v1beta2 exists
  * Kill DefaultCodec, replace it with "latest.Codec"
  * This updates the client and etcd to store the latest known version
* EmbeddedObject is per schema and per package now
* Move runtime.DefaultScheme to api.Scheme
* Split out WatchEvent since it's not an API object today, treat it
like a special object in api
* Kill DefaultResourceVersioner, instead place it on "latest" (as the
  package that understands all packages)
* Move objDiff to runtime.ObjectDiff

plugin/pkg/scheduler/factory/factory_test.go

@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/latest"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client/cache"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
@@ -113,7 +114,7 @@ func TestPollMinions(t *testing.T) {
 		ml := &api.MinionList{Items: item.minions}
 		handler := util.FakeHandler{
 			StatusCode:   200,
-			ResponseBody: latest.Codec.EncodeOrDie(ml),
+			ResponseBody: runtime.EncodeOrDie(latest.Codec, ml),
 			T:            t,
 		}
 		mux := http.NewServeMux()
@@ -140,7 +141,7 @@ func TestDefaultErrorFunc(t *testing.T) {
 	testPod := &api.Pod{JSONBase: api.JSONBase{ID: "foo"}}
 	handler := util.FakeHandler{
 		StatusCode:   200,
-		ResponseBody: latest.Codec.EncodeOrDie(testPod),
+		ResponseBody: runtime.EncodeOrDie(latest.Codec, testPod),
 		T:            t,
 	}
 	mux := http.NewServeMux()
@@ -259,7 +260,7 @@ func TestBind(t *testing.T) {
 			t.Errorf("Unexpected error: %v", err)
 			continue
 		}
-		expectedBody := latest.Codec.EncodeOrDie(item.binding)
+		expectedBody := runtime.EncodeOrDie(latest.Codec, item.binding)
 		handler.ValidateRequest(t, "/api/v1beta1/bindings", "POST", &expectedBody)
 	}
 }