[sheepdog] decouple logger from dog

[Liu Yuan]

On Fri, Nov 15, 2013 at 03:18:43AM +0900, MORITA Kazutaka wrote:
> At Tue, 12 Nov 2013 16:14:20 +0800,
> Liu Yuan wrote:
> > 
> > Use fprintf directly as we need
> 
> What's the benefit?  sd logger is designed to be able to use fprintf()
> for foreground programs.  In addition, we cannot completely decouple
> logger from dog anyway because dog can call sd_emerg() in panic().

The benefit is eliminate fprintf, might not be convincing enough. I didn't
notice dog use panic().

I'm going to patch logger to support stdout for foreground daemon.

Thanks
Yuan