dns: add port overriding support

hooklib/dns.h

@@ -4,6 +4,7 @@
 
 #include <stddef.h>
 void http_hook_init();
+void port_hook_init(unsigned short _startup_port, unsigned short _billing_port, unsigned short _aimedb_port);
 // if to_src is NULL, all lookups for from_src will fail
 HRESULT dns_hook_push(const wchar_t *from_src, const wchar_t *to_src);