Rewrite kubectl explain to use openapi

This removes all dependencies on swagger 1.2 for explain.

pkg/kubectl/explain/fields_printer_builder.go

@@ -0,0 +1,36 @@
+/*
+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 explain
+
+// fieldsPrinterBuilder builds either a regularFieldsPrinter or a
+// recursiveFieldsPrinter based on the argument.
+type fieldsPrinterBuilder struct {
+	Recursive bool
+}
+
+// BuildFieldsPrinter builds the appropriate fieldsPrinter.
+func (f fieldsPrinterBuilder) BuildFieldsPrinter(writer *Formatter) fieldsPrinter {
+	if f.Recursive {
+		return &recursiveFieldsPrinter{
+			Writer: writer,
+		}
+	}
+
+	return &regularFieldsPrinter{
+		Writer: writer,
+	}
+}