Better formatting

[GoogleCodeExporter]

Log4j has awesome formatting feature, why not log4go? The formatting in log4go 
is really strict, for instance, I don't want to see the timezone but I want to 
see the second and millisecond info, but I cannot do this. Can it be a little 
flexible?

Original issue reported on code.google.com by mty...@gmail.com on 24 Jun 2014 at 1:10

[GoogleCodeExporter]

I'd like to have  "%s" which means short version of soruce: e.g.:

     %S     github.com/user/project/package/somefile.Func:linenumber

     %s     somefile.Func:linenumber

Original comment by olivea...@gmail.com on 15 Jan 2015 at 5:35