Signed-off-by: John Howard <jhoward@microsoft.com>
Allows containerd.exe to run as a Windows service. eg
Register: `.\containerd.exe --register-service`
Start: `net start containerd`
...
Stop: `net stop containerd`
Unregister: `.\containerd.exe --unregister-service`
When running as a service, logs will go to the Windows application
event log.
