File Upload Fixes

Dunno why this was buggered again. ":back" doesn't seem to function as it used to.
Also, when uploading a file from page "foo", it's important to return to "foo" after
a successful upload, rather than redirecting to the HomePage.

Finally, a favicon tweak.

vendor/rails/actionpack/lib/action_controller/response.rb

@@ -144,7 +144,6 @@ module ActionController # :nodoc:
       set_content_length!
       convert_content_type!
       convert_language!
-      convert_expires!
       convert_cookies!
     end
 
@@ -244,10 +243,6 @@ module ActionController # :nodoc:
         headers["Content-Language"] = headers.delete("language") if headers["language"]
       end
 
-      def convert_expires!
-        headers["Expires"] = headers.delete("") if headers["expires"]
-      end
-
       def convert_cookies!
         headers['Set-Cookie'] = Array(headers['Set-Cookie']).compact
       end