Fix clicking on streams in left sidebar from subscriptions page.

We previously had 2 mechanisms for narrowing used by the left sidebar
-- the top few links used the hashchange mechanism, while the streams
links used a custom click handler.  Both were buggy -- the hashchange
one hadn't been updated to just select the first unread message,
whereas the click handler didn't change tabs.

Fixes #1141.

(imported from commit 8a8af974e78cc5c33937ac0078f04a9b5452b94a)

zephyr/static/js/hashchange.js

@@ -53,14 +53,8 @@ function parse_narrow(hash) {
         var operand  = decodeHashComponent(hash[i+1] || '');
         operators.push([operator, operand]);
     }
-    var new_selection;
-    if (current_msg_list.selected_id() !== -1) {
-        new_selection = current_msg_list.selected_id();
-    } else {
-        new_selection = page_params.initial_pointer;
-    }
     narrow.activate(operators, {
-        then_select_id: new_selection,
+        select_first_unread: true,
         change_hash:    false  // already set
     });
 }

zephyr/static/js/ui.js

@@ -985,13 +985,6 @@ $(function () {
         compose.start('private', {private_message_recipient: email});
         e.preventDefault();
     });
-
-    $('#stream_filters li').on('click', 'a', function (e) {
-        var stream = $(e.target).parents('li').data('name');
-        narrow.by('stream', stream, {select_first_unread: true});
-
-        e.preventDefault();
-    });
 });
 
 function sort_narrow_list() {