Provide a way of setting password for ext connections using internal ssh code

ExtConnection apparently has all the necessary stuff in place to initiate an "ext using ssh" connection on its own, without an external ssh command. However, there seems to be no way of setting the password for such connections: ext URLs are fixed to 4 tokens so you can set a username, but not a password (see AbstractCvsScmProvider - not misleading message that there are "too few tokens" when in fact there may be too many....). It's also not retrieved from a system property or such - so it's always "password is null", whatever you do.

Suggestion: try to get the SSH password from a System property.