Windows color support for CoLog

Uses go-colorable to display unix terminal colors on Windows. Behaviour for other systems is not altered.

package main

import (
	"log"

	"comail.io/go/colog"
	"comail.io/go/wincolog"
)

func main() {
	colog.Register()
	colog.SetOutput(wincolog.Stdout())
	log.Println("trace: Trace should be plain")
	log.Println("debug: Debug should be blue")
	log.Println("info: Info should be green")
	log.Println("warn: Warning should be yellow")
	log.Println("error: Error should be red")
	log.Println("alert: Alert should be white on re")
}