tracing logger (Refs #506)

DEPENDS ON https://github.com/tendermint/tmlibs/pull/21

cmd/tendermint/commands/root.go

@@ -8,6 +8,7 @@ import (
 
 	tmflags "github.com/tendermint/tendermint/cmd/tendermint/commands/flags"
 	cfg "github.com/tendermint/tendermint/config"
+	"github.com/tendermint/tmlibs/cli"
 	"github.com/tendermint/tmlibs/log"
 )
 
@@ -34,6 +35,9 @@ var RootCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
+		if viper.GetBool(cli.TraceFlag) {
+			logger = log.NewTracingLogger(logger)
+		}
 		return nil
 	},
 }