Don't receive notifications for messages on muted topics.

This doesn't address the more complicated case of someone @-mentioning
you on a muted topic, which consensus is you do want to get
information for, but we need to develop some infrastructure to present
that case to users clearly.

(imported from commit a4bc1e89c108fa8ba6eccc0a198eabf2231326ab)

static/js/notifications.js

@@ -308,6 +308,14 @@ function message_is_notifiable(message) {
     if (message.sent_by_me) {
         return false;
     }
+    if ((message.type === "stream") &&
+        !stream_data.in_home_view(message.stream)) {
+        return false;
+    }
+    if ((message.type === "stream") &&
+        muting.is_topic_muted(message.stream, message.subject)) {
+        return false;
+    }
 
     // Then, do any properties make it notifiable?
     if (message.type === "private") {