Request for review - change two include header files according to POSIX.1-2008

[Charles Lee]

Hi guys,

sys/unistd.h, sys/fcntl.h are not supported in AIX. And according to the 
POSIX.1-2008 (http://pubs.opengroup.org/onlinepubs/9699919799/), I have 
changed them to unistd.h and fcntl.h. The patch has been tested on both 
linux and aix.

I also change the header file in solaris, though I do not have a solaris 
machine on the hand. Hope it will not break the build :-)

The patch and webrev has been attached.

-- 
Yours Charles