按日切割和按大小切割同时打开的时候，历史Log日期错误

if w.MaxLines > 0 || w.MaxSize > 0 {
		for ; err == nil && num <= 999; num++ {
			fName = w.fileNameOnly + fmt.Sprintf(".%s.%03d%s", logTime.Format("2006-01-02"), num, w.suffix)//这块用的Logtime 是新一天的日期 应该用dailyOpenTime?
			_, err = os.Lstat(fName)
		}
	} else {
		fName = fmt.Sprintf("%s.%s%s", w.fileNameOnly, w.dailyOpenTime.Format("2006-01-02"), w.suffix)
		_, err = os.Lstat(fName)
		for ; err == nil && num <= 999; num++ {
			fName = w.fileNameOnly + fmt.Sprintf(".%s.%03d%s", w.dailyOpenTime.Format("2006-01-02"), num, w.suffix)
			_, err = os.Lstat(fName)
		}
	}

file {
filename = "log/gate.log"
daily = true
rotate = true
level = 3
max-lines = 0
max-size = 104857600
}

daily 和 max-size都开启,当到新一天的时候，比如2016-07-02，重命名07-01的旧日志用的新日期，把上面代码的logTime改为dailyOpenTime是否能解决？

[xujinzheng]

请见 #17 这个是从beego移植过来的,但beego的作者一直未更新