Garbage Collection of :form_keys

In each session, keep only the 30 most recent :form_keys generated by form_spam_protection.
This should be more than enough for ordinary usage, but prevents the session data from
becoming inordinately large.

Also, burnt-orange rulz!

app/views/admin/edit_web.rhtml

@@ -34,7 +34,7 @@
     <label for="color">Color:</label>
     <select id="color" name="color">
       <%= html_options({ 'Green' => '008B26', 'Purple' => '504685', 'Red' => 'DA0006', 
-                         'Orange' => 'FA6F00', 'Grey' => '8BA2B0' }, @web.color) %>
+                         'Orange' => 'C50', 'Grey' => '8BA2B0' }, @web.color) %>
     </select>
     <br/>
     <p>