Add Stdout and Stderr variables

Author: peterhellberg

Diff for: log.go

@@ -5,14 +5,21 @@ import (
 	"os"
 )
 
+// Stdout, and Stderr are open Files pointing to the standard output,
+// and standard error file descriptors.
+var (
+	Stdout = os.Stdout
+	Stderr = os.Stderr
+)
+
 // Log to standard output.
 func Log(format string, a ...interface{}) {
 	fmt.Printf(format+"\n", a...)
 }
 
 // Fatal prints to os.Stderr, followed by a call to os.Exit(1).
 func Fatal(v ...interface{}) {
-	fmt.Fprintln(os.Stderr, v...)
+	fmt.Fprintln(Stderr, v...)
 	os.Exit(1)
 }