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

Add description of new libmach.
diff --git a/man/man3/rsa.3 b/man/man3/rsa.3
index 58537bf..c138629 100644
--- a/man/man3/rsa.3
+++ b/man/man3/rsa.3
@@ -162,7 +162,7 @@
    "C=US ST=NJ L=07922 O=Lucent OU='Bell Labs' CN=Eric"
 .EE
 using the quoting conventions of
-.IR tokenize (2).
+.IR tokenize (3).
 .PP
 .I Asn1toRSApriv
 converts an ASN1 formatted RSA private key into the corresponding
@@ -189,14 +189,14 @@
 .SH SOURCE
 .B /sys/src/libsec
 .SH SEE ALSO
-.IR mp (2),
-.IR aes (2),
-.IR blowfish (2),
-.IR des (2),
-.IR dsa (2),
-.IR elgamal (2),
-.IR rc4 (2),
-.IR sechash (2),
-.IR prime (2),
-.IR rand (2),
+.IR mp (3),
+.IR aes (3),
+.IR blowfish (3),
+.IR des (3),
+.IR dsa (3),
+.IR elgamal (3),
+.IR rc4 (3),
+.IR sechash (3),
+.IR prime (3),
+.IR rand (3),
 .IR x509 (8)