recent_topics: Move launch button to top left sidebar.

Make dispaly `a` tag a block to so that it is clickable on
anywhere in the button space.

static/js/click_handlers.js

@@ -650,11 +650,6 @@ exports.initialize = function () {
         compose_actions.cancel();
     });
 
-    $("#recent_topics_icon").click(function (e) {
-        e.stopPropagation();
-        hashchange.go_to_location('recent_topics');
-    });
-
     $("#streams_inline_cog").click(function (e) {
         e.stopPropagation();
         hashchange.go_to_location('streams/subscribed');

static/styles/left-sidebar.scss

@@ -55,8 +55,7 @@ li.show-more-topics {
 }
 
 #streams_inline_cog,
-#streams_filter_icon,
-#recent_topics_icon {
+#streams_filter_icon {
     float: right;
     opacity: 0.50;
     font-size: 13px;
@@ -251,10 +250,15 @@ li.active-sub-filter {
 li.top_left_all_messages,
 .private_messages_header,
 li.top_left_mentions,
-li.top_left_starred_messages {
+li.top_left_starred_messages,
+li.top_left_recent_topics {
     position: relative;
     padding-top: 1px;
     padding-bottom: 1px;
+
+    a {
+        display: block;
+    }
 }
 
 .top_left_row {

templates/zerver/app/left_sidebar.html

@@ -56,11 +56,19 @@
                 </a>
                 <span class="arrow starred-messages-sidebar-menu-icon"><i class="zulip-icon ellipsis-v-solid" aria-hidden="true"></i></span>
             </li>
+            <li class="top_left_recent_topics top_left_row">
+                <a href="#recent_topics">
+                    <span class="filter-icon">
+                        <i class="fa fa-clock-o" aria-hidden="true"></i>
+                    </span>
+                    {#- squash whitespace -#}
+                    <span>{{ _('Recent topics') }}</span>
+                </a>
+            </li>
         </ul>
         <div id="streams_list" class="zoom-out">
             <div id="streams_header" class="zoom-in-hide"><h4 class="sidebar-title" data-toggle="tooltip" title="{{ _('Filter streams') }}">{{ _('STREAMS') }}</h4>
                 <i id="streams_inline_cog" class='fa fa-cog' aria-hidden="true" data-toggle="tooltip" title="{{ _('Subscribe, add, or configure streams') }}"></i>
-                <i id="recent_topics_icon" class='fa fa-clock-o' aria-hidden="true" data-toggle="tooltip" title="{{ _('Recent topics') }} (t)"></i>
                 <i id="streams_filter_icon" class='fa fa-search' aria-hidden="true" data-toggle="tooltip" title="{{ _('Filter streams') }} (q)"></i>
                 <div class="input-append notdisplayed stream_search_section">
                     <input class="stream-list-filter" type="text" autocomplete="off" placeholder="{{ _('Search streams') }}" />