Add strings pkg to hold strings utils

Replace funtions with strings pkg

Fix all references and rename the pkg

pkg/util/strings/strings.go

@@ -0,0 +1,47 @@
+/*
+Copyright 2014 The Kubernetes Authors 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 strings
+
+import (
+	"path"
+	"strings"
+)
+
+// Splits a fully qualified name and returns its namespace and name.
+// Assumes that the input 'str' has been validated.
+func SplitQualifiedName(str string) (string, string) {
+	parts := strings.Split(str, "/")
+	if len(parts) < 2 {
+		return "", str
+	}
+	return parts[0], parts[1]
+}
+
+// Joins 'namespace' and 'name' and returns a fully qualified name
+// Assumes that the input is valid.
+func JoinQualifiedName(namespace, name string) string {
+	return path.Join(namespace, name)
+}
+
+// Returns the first N slice of a string.
+func ShortenString(str string, n int) string {
+	if len(str) <= n {
+		return str
+	} else {
+		return str[:n]
+	}
+}