alecthomas/log4go — pull request #3 by cfxks1989 (2014-04-29 08:00:14+00:00)
Title: change the format of filename

Many logfiles need to be separated by date.
And the logfile name with the date will help us to find specific file.
So add date format in filelog.go
What's more, it is safer to close the file before rename it.