dynamic: The dynamic client no longer needs a special cased watch

By correctly handling content type negotiation, we can avoid the
need for a special version of watch and use the same code path as
typed clients.

Kubernetes-commit: 3f94f80b0a79293e54d7080aaf7a64d7df8b1d4a

dynamic/client_test.go

@@ -537,6 +537,8 @@ func TestWatch(t *testing.T) {
 				t.Errorf("Watch(%q) got query %s. wanted %s", tc.name, r.URL.RawQuery, tc.query)
 			}
 
+			w.Header().Set("Content-Type", "application/json")
+
 			enc := restclientwatch.NewEncoder(streaming.NewEncoder(w, unstructured.UnstructuredJSONScheme), unstructured.UnstructuredJSONScheme)
 			for _, e := range tc.events {
 				enc.Encode(&e)