(match_local_auth): new function
(find_auth_cookie): new function
(replace_cookie): don't just take the first auth cookie. based on
patch from Ake Sandgren <ake@@cs.umu.se>
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@6152 ec53bebd-3082-4978-b11e-865c3cabbd6b