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

Add description of new libmach.

man/man3/dsa.3

@@ -79,7 +79,7 @@ a key is created using a new
 and
 .B q
 generated by
-.IR DSAprimes (2).
+.IR DSAprimes (3).
 Otherwise,
 .B p
 and
@@ -121,12 +121,12 @@ are provided to manage signature storage.
 .SH SOURCE
 .B /sys/src/libsec
 .SH SEE ALSO
-.IR mp (2),
-.IR aes (2),
-.IR blowfish (2),
-.IR des (2),
-.IR rc4 (2),
-.IR rsa (2),
-.IR sechash (2),
-.IR prime (2),
-.IR rand (2)
+.IR mp (3),
+.IR aes (3),
+.IR blowfish (3),
+.IR des (3),
+.IR rc4 (3),
+.IR rsa (3),
+.IR sechash (3),
+.IR prime (3),
+.IR rand (3)