Move Resource functionality to its own package

Create a unified Builder object for working with files, selectors,
types, and items that makes it easier to get multi-object functionality.

Supports all of the behaviors previously in resource.go, but with
additional flexibility to allow multi-type retrieval and access, directories,
URLs, nested objects, and lists.

pkg/kubectl/resource/doc.go

@@ -0,0 +1,24 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package resource assists clients in dealing with RESTful objects that match the
+// Kubernetes API conventions. The Helper object provides simple CRUD operations
+// on resources. The Visitor interface makes it easy to deal with multiple resources
+// in bulk for retrieval and operation. The Builder object simplifies converting
+// standard command line arguments and parameters into a Visitor that can iterate
+// over all of the identified resources, whether on the server or on the local
+// filesystem.
+package resource