Windows node setup

[bobsira]

This pull request introduces several enhancements to the Hyper-V driver and Docker Machine library to support Windows Server VHD images. Key changes include:

Hyper-V Driver Modifications:

• Added WindowsVHDUrl and OS fields to the driver configuration.
• Updated the NewDriver function to initialize these fields with default values.
• Enhanced PreCreateCheck and Create functions to handle downloading and copying of Windows Server VHD images, based on the guest OS type.
• Modified various Hyper-V commands to support Windows Server configurations, such as setting up VM processors, memory, and hard disk drives specifically for Windows.

Docker Machine Library Enhancements:

• Updated method signatures to include a guest OS parameter.
• Added the DefineGuest function to differentiate guest OS.
• Introduced utility functions to manage Windows VHD images, including DownloadVHD, CopyWindowsIsoToMachineDir, and UpdateVHDCache.

New Download Handling:

• Added download_vhd.go for multi-part downloading of large VHD files with progress tracking.

SSH Command Handling:

• Added checks to prevent SSH command execution on Windows guest OS, as SSH is not supported in this environment.

These changes aim to provide robust support for Windows Server deployments in Docker Machine, enhancing compatibility and flexibility for users managing virtual machines on Hyper-V.