Beginning of rewrite apply merge-logic using visitor pattern.

Major changes:
- Don't generate a patch, instead generate the merged object so it can be used with PUT
- Separate tree parsing logic to collate items in a list from the delete / merge / replace / add logic when merging
- Use openapi for merge strategy metadata so it works with extensions and version skew
- Support multi-field mergekeys when merging lists
- Support replace strategy for maps
- Reduce complexity of generating order when merging lists - keep the locally defined order and append remote only-items

Continue to support:
- Explicitly setting fields to null
- Merging lists of primitives
- Don't randomize ordering when merging lists

TODO:
- Retain keys
- Conflict detection

pkg/kubectl/apply/parse/primitive_element.go

@@ -0,0 +1,30 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+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 parse
+
+import "k8s.io/kubernetes/pkg/kubectl/apply"
+
+// primitiveElement builds a new primitiveElement from a PrimitiveItem
+func (v ElementBuildingVisitor) primitiveElement(item *primitiveItem) (*apply.PrimitiveElement, error) {
+	result := &apply.PrimitiveElement{
+		HasElementData: item.HasElementData,
+		RawElementData: item.RawElementData,
+	}
+	result.Name = item.Name
+
+	return result, nil
+}