Updates related to SSH analysis.

- Some scripts used wrong SSH module/namespace scoping on events.
- Fix outdated notice documentation related to SSH password guessing.
- Add a unit test for SSH pasword guessing notice.

testing/btest/scripts/policy/protocols/ssh/detect-bruteforcing.bro

@@ -0,0 +1,5 @@
+# @TEST-EXEC: bro -C -r $TRACES/ssh/sshguess.pcap %INPUT
+# @TEST-EXEC: btest-diff notice.log
+
+@load protocols/ssh/detect-bruteforcing
+redef SSH::password_guesses_limit=10;