Move "common/config" common types into cfgtypes.

common/config/util.go

Index: common/config/util.go
diff --git a/common/config/util.go b/common/config/util.go
deleted file mode 100644
index 6567ba89254fbb68ba96dde8c141c85407d2f8eb..0000000000000000000000000000000000000000
--- a/common/config/util.go
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2015 The LUCI Authors. All rights reserved.
-// Use of this source code is governed under the Apache License, Version 2.0
-// that can be found in the LICENSE file.
-
-package config
-
-import (
-	"fmt"
-)
-
-// ProjectConfigSet returns the name of the ConfigSet associated with project.
-func ProjectConfigSet(project ProjectName) string {
-	return fmt.Sprintf("projects/%s", project)
-}