add mentions

app/templates/users/settings.html

@@ -26,6 +26,8 @@
       <option value='activity' {{ 'selected' if session['sort_by'] == 'activity' else '' }}>Latest activity</option>
       <option value='thread' {{ 'selected' if session['sort_by'] == 'thread' else '' }}>Thread creation date</option>
     </select>
+    <label for='display_name'>Display name</label>
+    <input type='text' id='display_name' name='display_name' value='{{ active_user.display_name }}' pattern="(?:[\w!#$%^*\(\)\-_=+\[\]\{\}\|;:,.?\s]{3,50})?" title='3-50 characters, no @, no <>, no &' placeholder='Optional. Will be shown in place of username.' autocomplete='off'></input>
     <label for='status'>Status</label>
     <input type='text' id='status' name='status' value='{{ active_user.status }}' maxlength=100 placeholder='Will be shown under your name. Max 100 characters.'>
     <label for='babycode-content'>Signature</label>