make klog sufficient for working with logr

As discussed in kubernetes/enhancements#3078, enabling
code that only imports klog for all logging makes life simpler for developers.

This was also the reason why KObj was added to klog instead of a separate
helper package.

imports.go

@@ -0,0 +1,38 @@
+/*
+Copyright 2021 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 klog
+
+import (
+	"github.com/go-logr/logr"
+)
+
+// The reason for providing these aliases is to allow code to work with logr
+// without directly importing it.
+
+// Logger in this package is exactly the same as logr.Logger.
+type Logger = logr.Logger
+
+// LogSink in this package is exactly the same as logr.LogSink.
+type LogSink = logr.LogSink
+
+// Runtimeinfo in this package is exactly the same as logr.RuntimeInfo.
+type RuntimeInfo = logr.RuntimeInfo
+
+var (
+	// New is an alias for logr.New.
+	New = logr.New
+)