Rewrite page(2) references to page(3).

Add description of new libmach.

man/man3/rendezvous.3

@@ -13,9 +13,9 @@ The rendezvous system call allows two processes to synchronize and
 exchange a value.
 In conjunction with the shared memory system calls
 (see
-.IR segattach (2)
+.IR segattach (3)
 and
-.IR fork (2)),
+.IR fork (3)),
 it enables parallel programs to control their scheduling.
 .PP
 Two processes wishing to synchronize call
@@ -42,7 +42,7 @@ inherited when a process forks, unless
 is set in the argument to
 .BR rfork ;
 see
-.IR fork (2).
+.IR fork (3).
 .PP
 If a rendezvous is interrupted the return value is
 .BR ~0 ,
@@ -50,8 +50,8 @@ so that value should not be used in normal communication.
 .SH SOURCE
 .B /sys/src/libc/9syscall
 .SH SEE ALSO
-.IR segattach (2),
-.IR fork (2)
+.IR segattach (3),
+.IR fork (3)
 .SH DIAGNOSTICS
 Sets
 .IR errstr .