[#108] "Error: Unencrypted communication not supported" with 0.8.0 and winrm #108

@adamedx  @muktaa 
It includes:
1> I've added changes to fix https://github.com/opscode/knife-windows/issues/108 issue.
2> @siddheshwar-more has fixed bug related to winrm session exit code

We don't know here if the user specified transport to be plaintext or if it is just plaintext because of the default, so we should print a message here saying that we're switching to ssl transport because it's required for domain authentication (is it?).