views: remove IP addresses from most pages.

Removed IP addresses from comments and from most other listing pages.
IPs take up a lot of space in many places (especially IPv6 addresses),
and in most of these pages they're rarely useful for catching
sockpuppets.

app/views/dmails/show.html.erb

@@ -8,9 +8,6 @@
         <li><strong>Sender</strong>: <%= link_to_user @dmail.from %></li>
         <li><strong>Recipient</strong>: <%= link_to_user @dmail.to %></li>
         <li><strong>Date</strong>: <%= compact_time(@dmail.created_at) %></li>
-        <% if CurrentUser.user.is_moderator? %>
-          <li><strong>Sender IP</strong>: <%= link_to_ip @dmail.creator_ip_addr %></li>
-        <% end %>
       </ul>
 
       <h3>Body</h3>