Sprint36

Fix for vnet create issue.
Fix for issue 11 - unable to list VM images while OS images work fine.
Fix for supplying SSH password.
The 'else if (!option.affinityGroup)' check is required. While creating the vm with 'virtual network' option, first we need to create hosted service. Hosted service can be created
in a location or affinity group. If user specified affinity group option then we use it, if user not specified it ('else if (!option.affinityGroup)'  case) then we use the affinity group associated with the virtual network.

The reason for no 'else' is there is no specific case to handle in 'else' case. Whether or not 'options.virtualNetworkAffinityGroupName' is set, we need to ensure either location or affinity group is set. Which is we are checking  after 'if (options.virtualNetworkAffinityGroupName)' block