Once 4302197 goes into core, we need to finish the rest of this
work.

The client handshaker should figure out what key types to use
(RSA/DSA) and then only call chooseClientAlias()
once. By passing in an array of keytypes, we should only
make one call, and let the keymanager decide whether
to use a rsa or dsa key, and not leave that decision
to our implementation.

Brad