subs: Remove complicated onlaunch triggers.

We can reliably just use hashchange.go_to_location()
when you click on "Stream Settings" in the left
sidebar popover.

static/js/stream_popover.js

@@ -209,12 +209,8 @@ exports.register_stream_handlers = function () {
         var sub = stream_popover_sub(e);
         exports.hide_stream_popover();
 
-        hashchange.go_to_location("#streams");
-        // the template for subs needs to render.
-
-        subs.onlaunch("narrow_to_row", function () {
-            $(".stream-row[data-stream-id='" + sub.stream_id + "']").click();
-        }, false);
+        var stream_edit_hash = hash_util.stream_edit_uri(sub);
+        hashchange.go_to_location(stream_edit_hash);
     });
 
     // Narrow to stream

static/js/subs.js

@@ -1,8 +1,5 @@
 var subs = (function () {
 
-var meta = {
-    callbacks: {},
-};
 var exports = {};
 
 exports.show_subs_pane = {
@@ -558,7 +555,6 @@ exports.setup_page = function (callback) {
 
         if (callback) {
             callback();
-            exports.onlaunchtrigger();
         }
     }
 
@@ -569,28 +565,6 @@ exports.setup_page = function (callback) {
     }
 };
 
-// add a function to run on subscription page launch by name,
-// and specify whether it should be kept or just run once (boolean).
-exports.onlaunch = function (name, callback, keep) {
-    meta.callbacks[name] = {
-        func: callback,
-        keep: keep,
-    };
-};
-
-exports.onlaunchtrigger = function () {
-    for (var x in meta.callbacks) {
-        if (typeof meta.callbacks[x].func === "function") {
-            meta.callbacks[x].func();
-
-            // delete if it should not be kept.
-            if (!meta.callbacks[x].keep) {
-                delete meta.callbacks[x];
-            }
-        }
-    }
-};
-
 exports.switch_to_stream_row = function (stream_id) {
     var stream_row = row_for_stream_id(stream_id);