When using a client SSL certificate that needs a password Subversion no longer
attempts to store the password in the auth cache. This is a regression from
1.7/neon where the password was stored.
When using neon the Subversion code decrypts the certificate using neon
functions, this allowed Subversion to determine whether a password was correct
and store it, see client_ssl_decrypt_cert() in session.c. When using serf the
Subversion code no longer decrypts the certificate and makes no attempt to store
the password.