func Logf(lvl level, format string, args ...interface{}) {
	Global.intLogf(lvl, format, args...)
}
Send a formatted log message easily
Wrapper for (*Logger).Logf
package log4go
import (
	"errors"
	"os"
	"fmt"
	"strings"
)
var (
	Global Logger
)
func init() {
	Global = NewDefaultLogger(DEBUG)
}
func LoadConfiguration(filename string) {
	Global.LoadConfiguration(filename)
}
func AddFilter(name string, lvl level, writer LogWriter) {
	Global.AddFilter(name, lvl, writer)
}
func Close() {
	Global.Close()
}
func Crash(args ...interface{}) {
	if len(args) > 0 {
		Global.intLogf(CRITICAL, strings.Repeat(" %v", len(args))[1:], args...)
	}
	panic(args)
}
func Crashf(format string, args ...interface{}) {
	Global.intLogf(CRITICAL, format, args...)
	Global.Close()  
	panic(fmt.Sprintf(format, args...))
}
func Exit(args ...interface{}) {
	if len(args) > 0 {
		Global.intLogf(ERROR, strings.Repeat(" %v", len(args))[1:], args...)
	}
	Global.Close()  
	os.Exit(0)
}
func Exitf(format string, args ...interface{}) {
	Global.intLogf(ERROR, format, args...)
	Global.Close()  
	os.Exit(0)
}
func Stderr(args ...interface{}) {
	if len(args) > 0 {
		Global.intLogf(ERROR, strings.Repeat(" %v", len(args))[1:], args...)
	}
}
func Stderrf(format string, args ...interface{}) {
	Global.intLogf(ERROR, format, args...)
}
func Stdout(args ...interface{}) {
	if len(args) > 0 {
		Global.intLogf(INFO, strings.Repeat(" %v", len(args))[1:], args...)
	}
}
func Stdoutf(format string, args ...interface{}) {
	Global.intLogf(INFO, format, args...)
}
func Log(lvl level, source, message string) {
	Global.Log(lvl, source, message)
}