[PATCH] Preserve bare backslashes in AF and TT

Hello,

    It looks like NTLM and possibly Negotiate authentication is broken
in trunk because Squid eats the bare backslash that AF responses use to
separate authentication domain and user names. With the backslash
removed, the merged domainuser name never matches, of course.

The attached patch fixes the problem in my tests. Is there a better way
to do this?

Thank you,

Alex.