rewrite topics routes to include id

app/templates/threads/thread.html

@@ -5,7 +5,7 @@
 {%- block content -%}
 {%- set td -%}
 <ul class="horizontal">
-<li>Started by <a href="{{url_for('users.user_page', username=started_by.username)}}">{{started_by.get_readable_name()}}</a> in topic <a href="{{url_for('topics.topic', slug=topic.slug)}}">{{topic.name}}</a></li>
+<li>Started by <a href="{{url_for('users.user_page', username=started_by.username)}}">{{started_by.get_readable_name()}}</a> in topic <a href="{{url_for('topics.topic_by_id', topic_id=topic.id)}}">{{topic.name}}</a></li>
 {%- if thread.locked() or thread.stickied() -%}
   {%- if thread.locked() -%}
   <li class="visible">Locked</li>

app/templates/topics/topic.html

@@ -16,7 +16,7 @@
   {%- if is_logged_in() and get_active_user().can_post_to_topic(topic) -%}
   <a href="{{url_for('threads.new', topic_id=topic.id)}}" class="linkbutton">New thread</a>
   {%- endif -%}
-  <a href="{{url_for('topics.feed', slug=topic.slug)}}" class="linkbutton rss">Subscribe via RSS</a>
+  <a href="{{url_for('topics.feed', topic_id=topic.id)}}" class="linkbutton rss">Subscribe via RSS</a>
   <form method="GET">
     <select name="sort_by">
       <option value="activity"{% if sort_by == 'activity' %}selected{% endif %}>Sorted by activity</option>

app/templates/topics/topics.html

@@ -13,7 +13,7 @@
 {%- for topic in topics -%}
 <div class="topic-info plank">
   <div class="title-container">
-    <a class="info" href="{{url_for('topics.topic', slug=topic.slug)}}">{{topic.name}}</a>
+    <a class="info" href="{{url_for('topics.topic_by_id', topic_id=topic.id)}}">{{topic.name}}</a>
   </div>
   <div>{{topic.description}}</div>
   <ul class="horizontal">