logging: first outlet receives logger error message

Abandons stderr special-casing:

* looks weird on shell and IO redirection to same file because of
interleaving of stdout and stderr
* better than a separate dedicated outlet because it does not require
additional configuration

fixes #28

BREAK SEMANTICS CONFIG

cmd/test.go

@@ -65,7 +65,7 @@ func init() {
 
 func testCmdGlobalInit(cmd *cobra.Command, args []string) {
 
-	out := logger.NewOutlets(WriterOutlet{&NoFormatter{}, os.Stderr})
+	out := logger.NewOutlets()
 	out.Add(WriterOutlet{&NoFormatter{}, os.Stdout}, logger.Info)
 	log := logger.NewLogger(out, 1*time.Second)
 	testCmdGlobal.log = log