Add features to support application as a test controller.

[brdeyo]

This is the long overdue feature for adding controller/agent support to the Virtual Client. The addition of the VirtualClient.Controller project allows the application to function as a controller for execution of operations against N-number of target systems through SSH. The following features are part of this initial changeset:

• Command line support for defining N-number of SSH target systems (e.g. --agent-ssh=anyuser@10.1.2.3;pass).
• Support for installation of the agent on a target system through SSH.
• Support for installation of packages on a target system through SSH.
• Support for installation of PowerShell on a target system through SSH for script-based automation extensibility.
• Support for installation of Python on a target system through SSH for script-based automation extensibility.
• Command line support for execution of an entire command line to a target system where an agent is installed through SSH.
• A few initial profiles to support "offline scenarios" where internet connectivity does not exist on a target/agent system.