Added notification for user about located VNC password & address

[sparshev]

Following VMX driver practices - allowing user to see the VNC password for debugging purposes. It should not be a security concern, because such password is autogenerated during the image build.

Looks like that:

==> tart-cli: Waiting for the VNC server credentials from Tart...
==> tart-cli: Retrieved VNC credentials, connecting...
    tart-cli: If you want to view the screen of the VM, connect via VNC with the password "thumb-genre-width-motion" to
    tart-cli: vnc://127.0.0.1:60612
==> tart-cli: Connected to the VNC!

fixes: #114