Refactor sync(1) code and manpage

and mark it as finished in README.

README

@@ -63,7 +63,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
 =* split           yes                             none
 =  sponge          non-posix                       none
    strings         no                              -a, -n, -t
-=  sync            non-posix                       none
+=* sync            non-posix                       none
 =  tail            no                              -c, -f
 =  tar             non-posix                       none
 =* tee             yes                             none

sync.1

@@ -1,4 +1,4 @@
-.Dd January 30, 2015
+.Dd February 8, 2015
 .Dt SYNC 1
 .Os sbase
 .Sh NAME
@@ -10,7 +10,7 @@
 .Nm
 invokes
 .Xr sync 2
-to flush all unwritten changes to the disk. This is
+to flush all unwritten changes to disk. This is
 usually done before shutting down, rebooting or halting.
 .Sh SEE ALSO
 .Xr fsync 2 ,

sync.c

@@ -1,6 +1,4 @@
 /* See LICENSE file for copyright and license details. */
-#include <stdio.h>
-#include <stdlib.h>
 #include <unistd.h>
 
 #include "util.h"