Thouhgs about cross-platform signals and process

[Yonggang Luo]

Seems signal handling are common and process fork are common in qemu,
I suggest wrapping those in utils library for easily and consistence access
across
different platforms(Win32/POSIX)


-- 
         此致
礼
罗勇刚
Yours
    sincerely,
Yonggang Luo