Add mandoc-manpage for sleep(1) and refactor the code a bit

and mark it as finished in README.

README

@@ -58,7 +58,7 @@ The following tools are implemented ('*' == finished, '#' == UTF-8 support,
 =* rm              yes                             (-i)
 =* rmdir           yes                             none
 =  setsid          non-posix                       none
-=  sleep           yes                             none
+=* sleep           yes                             none
    sort            no                              -m, -o, -d, -f, -i
    split           yes                             none
 =  sponge          non-posix                       none

sleep.1

@@ -1,11 +1,21 @@
-.TH SLEEP 1 sbase\-VERSION
-.SH NAME
-sleep \- wait for a number of seconds
-.SH SYNOPSIS
-.B sleep
-.I seconds
-.SH DESCRIPTION
-.B sleep
-waits until the given number of seconds have elapsed.
-.SH SEE ALSO
-.IR sleep (3)
+.Dd January 30, 2015
+.Dt SLEEP 1 sbase\-VERSION
+.Sh NAME
+.Nm sleep
+.Nd wait for a number of seconds
+.Sh SYNOPSIS
+.Nm sleep
+.Ar num
+.Sh DESCRIPTION
+.Nm
+waits for
+.Ar num
+seconds to elapse.
+.Sh SEE ALSO
+.Xr sleep 3
+.Sh STANDARDS
+The
+.Nm
+utility is compliant with the
+.St -p1003.1-2008
+specification.

sleep.c

@@ -7,13 +7,13 @@
 static void
 usage(void)
 {
-	eprintf("usage: %s seconds\n", argv0);
+	eprintf("usage: %s num\n", argv0);
 }
 
 int
 main(int argc, char *argv[])
 {
-	unsigned int seconds;
+	unsigned long seconds;
 
 	ARGBEGIN {
 	default: