'remember password' fixes

'remember password' fixes

Identities without 'remember password' checked never have their
password stored to disk in any manner.

The password will remain in uncacheable memory until the
identity selector process exits.

User is now prompted to enter a password any time an identity
without a password is about to be sent to a service. The
'add password' dialog now shows the display name, NAI, and
requesting service for the identity.