Paramiko as the ssh connection only prompts for a password 1 time

This shows up more when using bzr-explorer. However when trying to do something that requires remote access, it prompts for a password. If you type it incorrectly, it doesn't try again, and can leave the state a bit confused. (It is not always obvious how to retry the last action and get it to work.)

I think it would be reasonable to prompt several times, either the standard 3 attempts, or until the remote closes the connection, or until the user Cancels.