JS: Switch from Humbug to Zulip in user-visible text.

(imported from commit 968d4f4ac84a6612492d8d063ede7dab5a2c5786)

zephyr/static/js/blueslip.js

@@ -79,7 +79,7 @@ function report_error(msg, stack, opts) {
                 // probably try to reload anyway.
                 ui.report_message("Oops.  It seems something has gone wrong. " +
                                   "The error has been reported to the fine " +
-                                  "folks at Humbug, but, in the mean time, " +
+                                  "folks at Zulip, but, in the mean time, " +
                                   "please try reloading the page.",
                                   $("#home-error"), "alert-error");
             }

zephyr/static/js/notifications.js

@@ -86,7 +86,7 @@ exports.update_title_count = function (new_message_count) {
     var n;
 
     var new_title = (new_message_count ? ("(" + new_message_count + ") ") : "")
-        + page_params.domain + " - Humbug";
+        + page_params.domain + " - Zulip";
 
     if (document.title === new_title) {
         return;

zephyr/static/js/zephyr.js

@@ -64,7 +64,7 @@ $(function () {
     // feedback and should always show up as an autocomplete option.
     if (people_dict['feedback@humbughq.com'] === undefined){
         add_person({"email": "feedback@humbughq.com",
-                    "full_name": "Humbug Feedback Bot"});
+                    "full_name": "Zulip Feedback Bot"});
     }
 
     activity.set_user_statuses(page_params.initial_presences,