GH-234: rename Broxygen to Zeexygen along with roles/directives

* All "Broxygen" usages have been replaced in
  code, documentation, filenames, etc.

* Sphinx roles/directives like ":bro:see" are now ":zeek:see"

* The "--broxygen" command-line option is now "--zeexygen"

scripts/policy/protocols/ssh/detect-bruteforcing.zeek

@@ -11,7 +11,7 @@ module SSH;
 export {
 	redef enum Notice::Type += {
 		## Indicates that a host has been identified as crossing the
-		## :bro:id:`SSH::password_guesses_limit` threshold with
+		## :zeek:id:`SSH::password_guesses_limit` threshold with
 		## failed logins.
 		Password_Guessing,
 		## Indicates that a host previously identified as a "password

scripts/policy/protocols/ssh/geo-data.zeek

@@ -8,7 +8,7 @@ module SSH;
 export {
 	redef enum Notice::Type += {
 		## If an SSH login is seen to or from a "watched" country based
-		## on the :bro:id:`SSH::watched_countries` variable then this
+		## on the :zeek:id:`SSH::watched_countries` variable then this
 		## notice will be generated.
 		Watched_Country_Login,
 	};

scripts/policy/protocols/ssh/interesting-hostnames.zeek

@@ -12,7 +12,7 @@ export {
 	redef enum Notice::Type += {
 		## Generated if a login originates or responds with a host where
 		## the reverse hostname lookup resolves to a name matched by the
-		## :bro:id:`SSH::interesting_hostnames` regular expression.
+		## :zeek:id:`SSH::interesting_hostnames` regular expression.
 		Interesting_Hostname_Login,
 	};