[sheepdog] [PATCH RFC] employ gnu99 style of GCC

[MORITA Kazutaka]

> 
> One more question, does RHEL 5 support GNU-C99 fully? And other platform
> such as old debian, you know, many servers in production is very
> conventional and impossible to upgrade GCC.

We don't have to take into account at least RHEL5 because its kernel
doesn't support timerfd and signalfd and we cannot use sheepdog on it.

Thanks,

Kazutaka