4196 Use anonymous creator icon for anonymous creator inbox comments

https://code.google.com/p/otwarchive/issues/detail?id=4196

Show the anonymous creator icon on anonymous creator comments in inboxes.

Merge this after merging the new homepage, please -- the inbox comments get moved to a new partial in that pull request, so it's easier to wait. The actual change for this issue is as follows

Old code:
```ruby
<div class="icon">
  <% if !feedback_comment.pseud.nil? %>
    <% if feedback_comment.pseud.user.is_author_of?(feedback_comment.ultimate_parent) && feedback_comment.ultimate_parent.anonymous? %>
      <span class="visitor icon"><!-- visitor icon holder --></span>
    <% else %>
      <%= icon_display(feedback_comment.pseud.user, feedback_comment.pseud) %>
    <% end %>
  <% else %>
    <span class="visitor icon"><!-- visitor icon holder --></span>
  <% end %>
</div>
```

New code on line 4:
```ruby
<div class="icon">
  <% if !feedback_comment.pseud.nil? %>
    <% if feedback_comment.pseud.user.is_author_of?(feedback_comment.ultimate_parent) && feedback_comment.ultimate_parent.anonymous? %>
      <span class="anonymous icon"><!-- anonymous creator icon holder --></span>
    <% else %>
      <%= icon_display(feedback_comment.pseud.user, feedback_comment.pseud) %>
    <% end %>
  <% else %>
    <span class="visitor icon"><!-- visitor icon holder --></span>
  <% end %>
</div>
```