fix region to region communication

A little sad to introduce user/password into the cross region communication.
But we currently can not rely upon client side certs providing that protection layer, so username, password is our strategy for anand/5.3.

I'm leveraging the `v2_key` to generate a password. This will be unique per installation and requires that both machines have the same `v2_key`. This allows us to avoid having yet another shared secret between machines.

Added the non "happy path" for `vmdbws_controller`, so that is better tested.
No automated tests around the soap stuff in vmdbws_client.

If your machine has a server side cert, then that is saying you were locked down by ipa, and you can assume the server was locked down by ipa. If the server is locked down by verisign, then that will work too.

https://bugzilla.redhat.com/show_bug.cgi?id=1135072

/cc @gmcculloug @Fryguy 
Since both username and password are being passed in, perhaps `regional_credentials?` is more appropriate.