Intelligence framework checkpoint

- Basic API seems to works, but tests aren't updated yet.

 - Several scripts are available in policy/frameworks/intel that
   call the "seen" function to provide data into the intel
   framework to be tested.

 - Intel::policy is not done yet and needs to be discussed to
   figure out what it needs to have.

 - Running the intel framework and having it do something finally
   is really cool!

scripts/policy/frameworks/intel/http-url.bro

@@ -0,0 +1,16 @@
+@load base/frameworks/intel
+
+export {
+	redef enum Intel::Where += {
+		HTTP::IN_URL,
+	};
+}
+
+event http_message_done(c: connection, is_orig: bool, stat: http_message_stat)
+	{
+	if ( is_orig && c?$http )
+		Intel::seen([$str=HTTP::build_url(c$http),
+		             $str_type=Intel::URL,
+		             $conn=c,
+		             $where=HTTP::IN_URL]);
+	}