update ASP example to support user and org names containing multibyte characters

In many cases, Base64 encoding function in the IIS/AD bundle didn't work for names with multibyte characters. I replaced the contents of the base64.asp utility with the function [here](https://code.google.com/p/asplite/source/browse/trunk/Base64.asp?spec=svn31&r=31) and added a UTF-8 encoding function in the AD script itself. 

cc: @jcheatham, @morten, @pdeuter