when initialising, recognise keys in a different order.
1. read the public keyring
2. if a userid has been specified, use it
3. if not, check the configuration file (~/.gnupg/gpg.conf) for a
default user id
4, only read the secret keyring if we need to (decrypting or signing)
5. if signing, and we still don't have a userid, use the first key in
the secret keyring
6. if encrypting, and we still have no userid, use the first in the
public keyring
ssh keys remain the same as previously.